/*! PhotoSwipe - v4.1.2 - 2017-04-05
 * http://photoswipe.com
 * Copyright (c) 2017 Dmitry Semenov; */
var PhotoSwipe = function() {

    'use strict';
    var PhotoSwipe = function(template, UiClass, items, options) {

        /*>>framework-bridge*/
        /**
         *
         * Set of generic functions used by gallery.
         * 
         * You're free to modify anything here as long as functionality is kept.
         * 
         */
        var framework = {
            features: null,
            bind: function(target, type, listener, unbind) {
                var methodName = (unbind ? 'remove' : 'add') + 'EventListener';
                type = type.split(' ');
                for (var i = 0; i < type.length; i++) {
                    if (type[i]) {
                        target[methodName](type[i], listener, false);
                    }
                }
            },
            isArray: function(obj) {
                return (obj instanceof Array);
            },
            createEl: function(classes, tag) {
                var el = document.createElement(tag || 'div');
                if (classes) {
                    el.className = classes;
                }
                return el;
            },
            getScrollY: function() {
                var yOffset = window.pageYOffset;
                return yOffset !== undefined ? yOffset : document.documentElement.scrollTop;
            },
            unbind: function(target, type, listener) {
                framework.bind(target, type, listener, true);
            },
            removeClass: function(el, className) {
                var reg = new RegExp('(\\s|^)' + className + '(\\s|$)');
                el.className = el.className.replace(reg, ' ').replace(/^\s\s*/, '').replace(/\s\s*$/, '');
            },
            addClass: function(el, className) {
                if (!framework.hasClass(el, className)) {
                    el.className += (el.className ? ' ' : '') + className;
                }
            },
            hasClass: function(el, className) {
                return el.className && new RegExp('(^|\\s)' + className + '(\\s|$)').test(el.className);
            },
            getChildByClass: function(parentEl, childClassName) {
                var node = parentEl.firstChild;
                while (node) {
                    if (framework.hasClass(node, childClassName)) {
                        return node;
                    }
                    node = node.nextSibling;
                }
            },
            arraySearch: function(array, value, key) {
                var i = array.length;
                while (i--) {
                    if (array[i][key] === value) {
                        return i;
                    }
                }
                return -1;
            },
            extend: function(o1, o2, preventOverwrite) {
                for (var prop in o2) {
                    if (o2.hasOwnProperty(prop)) {
                        if (preventOverwrite && o1.hasOwnProperty(prop)) {
                            continue;
                        }
                        o1[prop] = o2[prop];
                    }
                }
            },
            easing: {
                sine: {
                    out: function(k) {
                        return Math.sin(k * (Math.PI / 2));
                    },
                    inOut: function(k) {
                        return -(Math.cos(Math.PI * k) - 1) / 2;
                    }
                },
                cubic: {
                    out: function(k) {
                        return --k * k * k + 1;
                    }
                }
                /*
                    elastic: {
                        out: function ( k ) {

                            var s, a = 0.1, p = 0.4;
                            if ( k === 0 ) return 0;
                            if ( k === 1 ) return 1;
                            if ( !a || a < 1 ) { a = 1; s = p / 4; }
                            else s = p * Math.asin( 1 / a ) / ( 2 * Math.PI );
                            return ( a * Math.pow( 2, - 10 * k) * Math.sin( ( k - s ) * ( 2 * Math.PI ) / p ) + 1 );

                        },
                    },
                    back: {
                        out: function ( k ) {
                            var s = 1.70158;
                            return --k * k * ( ( s + 1 ) * k + s ) + 1;
                        }
                    }
                */
            },

            /**
             * 
             * @return {object}
             * 
             * {
             *  raf : request animation frame function
             *  caf : cancel animation frame function
             *  transfrom : transform property key (with vendor), or null if not supported
             *  oldIE : IE8 or below
             * }
             * 
             */
            detectFeatures: function() {
                if (framework.features) {
                    return framework.features;
                }
                var helperEl = framework.createEl(),
                    helperStyle = helperEl.style,
                    vendor = '',
                    features = {};

                // IE8 and below
                features.oldIE = document.all && !document.addEventListener;

                features.touch = 'ontouchstart' in window;

                if (window.requestAnimationFrame) {
                    features.raf = window.requestAnimationFrame;
                    features.caf = window.cancelAnimationFrame;
                }

                features.pointerEvent = navigator.pointerEnabled || navigator.msPointerEnabled;

                // fix false-positive detection of old Android in new IE
                // (IE11 ua string contains "Android 4.0")

                if (!features.pointerEvent) {

                    var ua = navigator.userAgent;

                    // Detect if device is iPhone or iPod and if it's older than iOS 8
                    // http://stackoverflow.com/a/14223920
                    // 
                    // This detection is made because of buggy top/bottom toolbars
                    // that don't trigger window.resize event.
                    // For more info refer to _isFixedPosition variable in core.js

                    if (/iP(hone|od)/.test(navigator.platform)) {
                        var v = (navigator.appVersion).match(/OS (\d+)_(\d+)_?(\d+)?/);
                        if (v && v.length > 0) {
                            v = parseInt(v[1], 10);
                            if (v >= 1 && v < 8) {
                                features.isOldIOSPhone = true;
                            }
                        }
                    }

                    // Detect old Android (before KitKat)
                    // due to bugs related to position:fixed
                    // http://stackoverflow.com/questions/7184573/pick-up-the-android-version-in-the-browser-by-javascript

                    var match = ua.match(/Android\s([0-9\.]*)/);
                    var androidversion = match ? match[1] : 0;
                    androidversion = parseFloat(androidversion);
                    if (androidversion >= 1) {
                        if (androidversion < 4.4) {
                            features.isOldAndroid = true; // for fixed position bug & performance
                        }
                        features.androidVersion = androidversion; // for touchend bug
                    }
                    features.isMobileOpera = /opera mini|opera mobi/i.test(ua);

                    // p.s. yes, yes, UA sniffing is bad, propose your solution for above bugs.
                }

                var styleChecks = ['transform', 'perspective', 'animationName'],
                    vendors = ['', 'webkit', 'Moz', 'ms', 'O'],
                    styleCheckItem,
                    styleName;

                for (var i = 0; i < 4; i++) {
                    vendor = vendors[i];

                    for (var a = 0; a < 3; a++) {
                        styleCheckItem = styleChecks[a];

                        // uppercase first letter of property name, if vendor is present
                        styleName = vendor + (vendor ?
                            styleCheckItem.charAt(0).toUpperCase() + styleCheckItem.slice(1) :
                            styleCheckItem);

                        if (!features[styleCheckItem] && styleName in helperStyle) {
                            features[styleCheckItem] = styleName;
                        }
                    }

                    if (vendor && !features.raf) {
                        vendor = vendor.toLowerCase();
                        features.raf = window[vendor + 'RequestAnimationFrame'];
                        if (features.raf) {
                            features.caf = window[vendor + 'CancelAnimationFrame'] ||
                                window[vendor + 'CancelRequestAnimationFrame'];
                        }
                    }
                }

                if (!features.raf) {
                    var lastTime = 0;
                    features.raf = function(fn) {
                        var currTime = new Date().getTime();
                        var timeToCall = Math.max(0, 16 - (currTime - lastTime));
                        var id = window.setTimeout(function() { fn(currTime + timeToCall); }, timeToCall);
                        lastTime = currTime + timeToCall;
                        return id;
                    };
                    features.caf = function(id) { clearTimeout(id); };
                }

                // Detect SVG support
                features.svg = !!document.createElementNS &&
                    !!document.createElementNS('http://www.w3.org/2000/svg', 'svg').createSVGRect;

                framework.features = features;

                return features;
            }
        };

        framework.detectFeatures();

        // Override addEventListener for old versions of IE
        if (framework.features.oldIE) {

            framework.bind = function(target, type, listener, unbind) {

                type = type.split(' ');

                var methodName = (unbind ? 'detach' : 'attach') + 'Event',
                    evName,
                    _handleEv = function() {
                        listener.handleEvent.call(listener);
                    };

                for (var i = 0; i < type.length; i++) {
                    evName = type[i];
                    if (evName) {

                        if (typeof listener === 'object' && listener.handleEvent) {
                            if (!unbind) {
                                listener['oldIE' + evName] = _handleEv;
                            } else {
                                if (!listener['oldIE' + evName]) {
                                    return false;
                                }
                            }

                            target[methodName]('on' + evName, listener['oldIE' + evName]);
                        } else {
                            target[methodName]('on' + evName, listener);
                        }

                    }
                }
            };

        }

        /*>>framework-bridge*/

        /*>>core*/
        //function(template, UiClass, items, options)

        var self = this;

        /**
         * Static vars, don't change unless you know what you're doing.
         */
        var DOUBLE_TAP_RADIUS = 25,
            NUM_HOLDERS = 3;

        /**
         * Options
         */
        var _options = {
            allowPanToNext: true,
            spacing: 0.12,
            bgOpacity: 1,
            mouseUsed: false,
            loop: false,
            pinchToClose: true,
            closeOnScroll: true,
            closeOnVerticalDrag: true,
            verticalDragRange: 0.75,
            hideAnimationDuration: 333,
            showAnimationDuration: 333,
            showHideOpacity: true,
            focus: true,
            escKey: true,
            arrowKeys: true,
            mainScrollEndFriction: 0.35,
            panEndFriction: 0.35,
            isClickableElement: function(el) {
                return el.tagName === 'A';
            },
            getDoubleTapZoom: function(isMouseClick, item) {
                if (isMouseClick) {
                    return 1;
                } else {
                    return item.initialZoomLevel < 0.7 ? 1 : 1.33;
                }
            },
            maxSpreadZoom: 1.5,
            modal: true,

            // not fully implemented yet
            scaleMode: 'fit' // TODO
        };
        framework.extend(_options, options);


        /**
         * Private helper variables & functions
         */

        var _getEmptyPoint = function() {
            return { x: 0, y: 0 };
        };

        var _isOpen,
            _isDestroying,
            _closedByScroll,
            _currentItemIndex,
            _containerStyle,
            _containerShiftIndex,
            _currPanDist = _getEmptyPoint(),
            _startPanOffset = _getEmptyPoint(),
            _panOffset = _getEmptyPoint(),
            _upMoveEvents, // drag move, drag end & drag cancel events array
            _downEvents, // drag start events array
            _globalEventHandlers,
            _viewportSize = {},
            _currZoomLevel,
            _startZoomLevel,
            _translatePrefix,
            _translateSufix,
            _updateSizeInterval,
            _itemsNeedUpdate,
            _currPositionIndex = 0,
            _offset = {},
            _slideSize = _getEmptyPoint(), // size of slide area, including spacing
            _itemHolders,
            _prevItemIndex,
            _indexDiff = 0, // difference of indexes since last content update
            _dragStartEvent,
            _dragMoveEvent,
            _dragEndEvent,
            _dragCancelEvent,
            _transformKey,
            _pointerEventEnabled,
            _isFixedPosition = true,
            _likelyTouchDevice,
            _modules = [],
            _requestAF,
            _cancelAF,
            _initalClassName,
            _initalWindowScrollY,
            _oldIE,
            _currentWindowScrollY,
            _features,
            _windowVisibleSize = {},
            _renderMaxResolution = false,
            _orientationChangeTimeout,


            // Registers PhotoSWipe module (History, Controller ...)
            _registerModule = function(name, module) {
                framework.extend(self, module.publicMethods);
                _modules.push(name);
            },

            _getLoopedId = function(index) {
                var numSlides = _getNumItems();
                if (index > numSlides - 1) {
                    return index - numSlides;
                } else if (index < 0) {
                    return numSlides + index;
                }
                return index;
            },

            // Micro bind/trigger
            _listeners = {},
            _listen = function(name, fn) {
                if (!_listeners[name]) {
                    _listeners[name] = [];
                }
                return _listeners[name].push(fn);
            },
            _shout = function(name) {
                var listeners = _listeners[name];

                if (listeners) {
                    var args = Array.prototype.slice.call(arguments);
                    args.shift();

                    for (var i = 0; i < listeners.length; i++) {
                        listeners[i].apply(self, args);
                    }
                }
            },

            _getCurrentTime = function() {
                return new Date().getTime();
            },
            _applyBgOpacity = function(opacity) {
                _bgOpacity = opacity;
                self.bg.style.opacity = opacity * _options.bgOpacity;
            },

            _applyZoomTransform = function(styleObj, x, y, zoom, item) {
                if (!_renderMaxResolution || (item && item !== self.currItem)) {
                    zoom = zoom / (item ? item.fitRatio : self.currItem.fitRatio);
                }

                styleObj[_transformKey] = _translatePrefix + x + 'px, ' + y + 'px' + _translateSufix + ' scale(' + zoom + ')';
            },
            _applyCurrentZoomPan = function(allowRenderResolution) {
                if (_currZoomElementStyle) {

                    if (allowRenderResolution) {
                        if (_currZoomLevel > self.currItem.fitRatio) {
                            if (!_renderMaxResolution) {
                                _setImageSize(self.currItem, false, true);
                                _renderMaxResolution = true;
                            }
                        } else {
                            if (_renderMaxResolution) {
                                _setImageSize(self.currItem);
                                _renderMaxResolution = false;
                            }
                        }
                    }


                    _applyZoomTransform(_currZoomElementStyle, _panOffset.x, _panOffset.y, _currZoomLevel);
                }
            },
            _applyZoomPanToItem = function(item) {
                if (item.container) {

                    _applyZoomTransform(item.container.style,
                        item.initialPosition.x,
                        item.initialPosition.y,
                        item.initialZoomLevel,
                        item);
                }
            },
            _setTranslateX = function(x, elStyle) {
                elStyle[_transformKey] = _translatePrefix + x + 'px, 0px' + _translateSufix;
            },
            _moveMainScroll = function(x, dragging) {

                if (!_options.loop && dragging) {
                    var newSlideIndexOffset = _currentItemIndex + (_slideSize.x * _currPositionIndex - x) / _slideSize.x,
                        delta = Math.round(x - _mainScrollPos.x);

                    if ((newSlideIndexOffset < 0 && delta > 0) ||
                        (newSlideIndexOffset >= _getNumItems() - 1 && delta < 0)) {
                        x = _mainScrollPos.x + delta * _options.mainScrollEndFriction;
                    }
                }

                _mainScrollPos.x = x;
                _setTranslateX(x, _containerStyle);
            },
            _calculatePanOffset = function(axis, zoomLevel) {
                var m = _midZoomPoint[axis] - _offset[axis];
                return _startPanOffset[axis] + _currPanDist[axis] + m - m * (zoomLevel / _startZoomLevel);
            },

            _equalizePoints = function(p1, p2) {
                p1.x = p2.x;
                p1.y = p2.y;
                if (p2.id) {
                    p1.id = p2.id;
                }
            },
            _roundPoint = function(p) {
                p.x = Math.round(p.x);
                p.y = Math.round(p.y);
            },

            _mouseMoveTimeout = null,
            _onFirstMouseMove = function() {
                // Wait until mouse move event is fired at least twice during 100ms
                // We do this, because some mobile browsers trigger it on touchstart
                if (_mouseMoveTimeout) {
                    framework.unbind(document, 'mousemove', _onFirstMouseMove);
                    framework.addClass(template, 'pswp--has_mouse');
                    _options.mouseUsed = true;
                    _shout('mouseUsed');
                }
                _mouseMoveTimeout = setTimeout(function() {
                    _mouseMoveTimeout = null;
                }, 100);
            },

            _bindEvents = function() {
                framework.bind(document, 'keydown', self);

                if (_features.transform) {
                    // don't bind click event in browsers that don't support transform (mostly IE8)
                    framework.bind(self.scrollWrap, 'click', self);
                }


                if (!_options.mouseUsed) {
                    framework.bind(document, 'mousemove', _onFirstMouseMove);
                }

                framework.bind(window, 'resize scroll orientationchange', self);

                _shout('bindEvents');
            },

            _unbindEvents = function() {
                framework.unbind(window, 'resize scroll orientationchange', self);
                framework.unbind(window, 'scroll', _globalEventHandlers.scroll);
                framework.unbind(document, 'keydown', self);
                framework.unbind(document, 'mousemove', _onFirstMouseMove);

                if (_features.transform) {
                    framework.unbind(self.scrollWrap, 'click', self);
                }

                if (_isDragging) {
                    framework.unbind(window, _upMoveEvents, self);
                }

                clearTimeout(_orientationChangeTimeout);

                _shout('unbindEvents');
            },

            _calculatePanBounds = function(zoomLevel, update) {
                var bounds = _calculateItemSize(self.currItem, _viewportSize, zoomLevel);
                if (update) {
                    _currPanBounds = bounds;
                }
                return bounds;
            },

            _getMinZoomLevel = function(item) {
                if (!item) {
                    item = self.currItem;
                }
                return item.initialZoomLevel;
            },
            _getMaxZoomLevel = function(item) {
                if (!item) {
                    item = self.currItem;
                }
                return item.w > 0 ? _options.maxSpreadZoom : 1;
            },

            // Return true if offset is out of the bounds
            _modifyDestPanOffset = function(axis, destPanBounds, destPanOffset, destZoomLevel) {
                if (destZoomLevel === self.currItem.initialZoomLevel) {
                    destPanOffset[axis] = self.currItem.initialPosition[axis];
                    return true;
                } else {
                    destPanOffset[axis] = _calculatePanOffset(axis, destZoomLevel);

                    if (destPanOffset[axis] > destPanBounds.min[axis]) {
                        destPanOffset[axis] = destPanBounds.min[axis];
                        return true;
                    } else if (destPanOffset[axis] < destPanBounds.max[axis]) {
                        destPanOffset[axis] = destPanBounds.max[axis];
                        return true;
                    }
                }
                return false;
            },

            _setupTransforms = function() {

                if (_transformKey) {
                    // setup 3d transforms
                    var allow3dTransform = _features.perspective && !_likelyTouchDevice;
                    _translatePrefix = 'translate' + (allow3dTransform ? '3d(' : '(');
                    _translateSufix = _features.perspective ? ', 0px)' : ')';
                    return;
                }

                // Override zoom/pan/move functions in case old browser is used (most likely IE)
                // (so they use left/top/width/height, instead of CSS transform)

                _transformKey = 'left';
                framework.addClass(template, 'pswp--ie');

                _setTranslateX = function(x, elStyle) {
                    elStyle.left = x + 'px';
                };
                _applyZoomPanToItem = function(item) {

                    var zoomRatio = item.fitRatio > 1 ? 1 : item.fitRatio,
                        s = item.container.style,
                        w = zoomRatio * item.w,
                        h = zoomRatio * item.h;

                    s.width = w + 'px';
                    s.height = h + 'px';
                    s.left = item.initialPosition.x + 'px';
                    s.top = item.initialPosition.y + 'px';

                };
                _applyCurrentZoomPan = function() {
                    if (_currZoomElementStyle) {

                        var s = _currZoomElementStyle,
                            item = self.currItem,
                            zoomRatio = item.fitRatio > 1 ? 1 : item.fitRatio,
                            w = zoomRatio * item.w,
                            h = zoomRatio * item.h;

                        s.width = w + 'px';
                        s.height = h + 'px';


                        s.left = _panOffset.x + 'px';
                        s.top = _panOffset.y + 'px';
                    }

                };
            },

            _onKeyDown = function(e) {
                var keydownAction = '';
                if (_options.escKey && e.keyCode === 27) {
                    keydownAction = 'close';
                } else if (_options.arrowKeys) {
                    if (e.keyCode === 37) {
                        keydownAction = 'prev';
                    } else if (e.keyCode === 39) {
                        keydownAction = 'next';
                    }
                }

                if (keydownAction) {
                    // don't do anything if special key pressed to prevent from overriding default browser actions
                    // e.g. in Chrome on Mac cmd+arrow-left returns to previous page
                    if (!e.ctrlKey && !e.altKey && !e.shiftKey && !e.metaKey) {
                        if (e.preventDefault) {
                            e.preventDefault();
                        } else {
                            e.returnValue = false;
                        }
                        self[keydownAction]();
                    }
                }
            },

            _onGlobalClick = function(e) {
                if (!e) {
                    return;
                }

                // don't allow click event to pass through when triggering after drag or some other gesture
                if (_moved || _zoomStarted || _mainScrollAnimating || _verticalDragInitiated) {
                    e.preventDefault();
                    e.stopPropagation();
                }
            },

            _updatePageScrollOffset = function() {
                self.setScrollOffset(0, framework.getScrollY());
            };







        // Micro animation engine
        var _animations = {},
            _numAnimations = 0,
            _stopAnimation = function(name) {
                if (_animations[name]) {
                    if (_animations[name].raf) {
                        _cancelAF(_animations[name].raf);
                    }
                    _numAnimations--;
                    delete _animations[name];
                }
            },
            _registerStartAnimation = function(name) {
                if (_animations[name]) {
                    _stopAnimation(name);
                }
                if (!_animations[name]) {
                    _numAnimations++;
                    _animations[name] = {};
                }
            },
            _stopAllAnimations = function() {
                for (var prop in _animations) {

                    if (_animations.hasOwnProperty(prop)) {
                        _stopAnimation(prop);
                    }

                }
            },
            _animateProp = function(name, b, endProp, d, easingFn, onUpdate, onComplete) {
                var startAnimTime = _getCurrentTime(),
                    t;
                _registerStartAnimation(name);

                var animloop = function() {
                    if (_animations[name]) {

                        t = _getCurrentTime() - startAnimTime; // time diff
                        //b - beginning (start prop)
                        //d - anim duration

                        if (t >= d) {
                            _stopAnimation(name);
                            onUpdate(endProp);
                            if (onComplete) {
                                onComplete();
                            }
                            return;
                        }
                        onUpdate((endProp - b) * easingFn(t / d) + b);

                        _animations[name].raf = _requestAF(animloop);
                    }
                };
                animloop();
            };



        var publicMethods = {

            // make a few local variables and functions public
            shout: _shout,
            listen: _listen,
            viewportSize: _viewportSize,
            options: _options,

            isMainScrollAnimating: function() {
                return _mainScrollAnimating;
            },
            getZoomLevel: function() {
                return _currZoomLevel;
            },
            getCurrentIndex: function() {
                return _currentItemIndex;
            },
            isDragging: function() {
                return _isDragging;
            },
            isZooming: function() {
                return _isZooming;
            },
            setScrollOffset: function(x, y) {
                _offset.x = x;
                _currentWindowScrollY = _offset.y = y;
                _shout('updateScrollOffset', _offset);
            },
            applyZoomPan: function(zoomLevel, panX, panY, allowRenderResolution) {
                _panOffset.x = panX;
                _panOffset.y = panY;
                _currZoomLevel = zoomLevel;
                _applyCurrentZoomPan(allowRenderResolution);
            },

            init: function() {

                if (_isOpen || _isDestroying) {
                    return;
                }

                var i;

                self.framework = framework; // basic functionality
                self.template = template; // root DOM element of PhotoSwipe
                self.bg = framework.getChildByClass(template, 'pswp__bg');

                _initalClassName = template.className;
                _isOpen = true;

                _features = framework.detectFeatures();
                _requestAF = _features.raf;
                _cancelAF = _features.caf;
                _transformKey = _features.transform;
                _oldIE = _features.oldIE;

                self.scrollWrap = framework.getChildByClass(template, 'pswp__scroll-wrap');
                self.container = framework.getChildByClass(self.scrollWrap, 'pswp__container');

                _containerStyle = self.container.style; // for fast access

                // Objects that hold slides (there are only 3 in DOM)
                self.itemHolders = _itemHolders = [
                    { el: self.container.children[0], wrap: 0, index: -1 },
                    { el: self.container.children[1], wrap: 0, index: -1 },
                    { el: self.container.children[2], wrap: 0, index: -1 }
                ];

                // hide nearby item holders until initial zoom animation finishes (to avoid extra Paints)
                _itemHolders[0].el.style.display = _itemHolders[2].el.style.display = 'none';

                _setupTransforms();

                // Setup global events
                _globalEventHandlers = {
                    resize: self.updateSize,

                    // Fixes: iOS 10.3 resize event
                    // does not update scrollWrap.clientWidth instantly after resize
                    // https://github.com/dimsemenov/PhotoSwipe/issues/1315
                    orientationchange: function() {
                        clearTimeout(_orientationChangeTimeout);
                        _orientationChangeTimeout = setTimeout(function() {
                            if (_viewportSize.x !== self.scrollWrap.clientWidth) {
                                self.updateSize();
                            }
                        }, 500);
                    },
                    scroll: _updatePageScrollOffset,
                    keydown: _onKeyDown,
                    click: _onGlobalClick
                };

                // disable show/hide effects on old browsers that don't support CSS animations or transforms, 
                // old IOS, Android and Opera mobile. Blackberry seems to work fine, even older models.
                var oldPhone = _features.isOldIOSPhone || _features.isOldAndroid || _features.isMobileOpera;
                if (!_features.animationName || !_features.transform || oldPhone) {
                    _options.showAnimationDuration = _options.hideAnimationDuration = 0;
                }

                // init modules
                for (i = 0; i < _modules.length; i++) {
                    self['init' + _modules[i]]();
                }

                // init
                if (UiClass) {
                    var ui = self.ui = new UiClass(self, framework);
                    ui.init();
                }

                _shout('firstUpdate');
                _currentItemIndex = _currentItemIndex || _options.index || 0;
                // validate index
                if (isNaN(_currentItemIndex) || _currentItemIndex < 0 || _currentItemIndex >= _getNumItems()) {
                    _currentItemIndex = 0;
                }
                self.currItem = _getItemAt(_currentItemIndex);


                if (_features.isOldIOSPhone || _features.isOldAndroid) {
                    _isFixedPosition = false;
                }

                template.setAttribute('aria-hidden', 'false');
                if (_options.modal) {
                    if (!_isFixedPosition) {
                        template.style.position = 'absolute';
                        template.style.top = framework.getScrollY() + 'px';
                    } else {
                        template.style.position = 'fixed';
                    }
                }

                if (_currentWindowScrollY === undefined) {
                    _shout('initialLayout');
                    _currentWindowScrollY = _initalWindowScrollY = framework.getScrollY();
                }

                // add classes to root element of PhotoSwipe
                var rootClasses = 'pswp--open ';
                if (_options.mainClass) {
                    rootClasses += _options.mainClass + ' ';
                }
                if (_options.showHideOpacity) {
                    rootClasses += 'pswp--animate_opacity ';
                }
                rootClasses += _likelyTouchDevice ? 'pswp--touch' : 'pswp--notouch';
                rootClasses += _features.animationName ? ' pswp--css_animation' : '';
                rootClasses += _features.svg ? ' pswp--svg' : '';
                framework.addClass(template, rootClasses);

                self.updateSize();

                // initial update
                _containerShiftIndex = -1;
                _indexDiff = null;
                for (i = 0; i < NUM_HOLDERS; i++) {
                    _setTranslateX((i + _containerShiftIndex) * _slideSize.x, _itemHolders[i].el.style);
                }

                if (!_oldIE) {
                    framework.bind(self.scrollWrap, _downEvents, self); // no dragging for old IE
                }

                _listen('initialZoomInEnd', function() {
                    self.setContent(_itemHolders[0], _currentItemIndex - 1);
                    self.setContent(_itemHolders[2], _currentItemIndex + 1);

                    _itemHolders[0].el.style.display = _itemHolders[2].el.style.display = 'block';

                    if (_options.focus) {
                        // focus causes layout, 
                        // which causes lag during the animation, 
                        // that's why we delay it untill the initial zoom transition ends
                        template.focus();
                    }


                    _bindEvents();
                });

                // set content for center slide (first time)
                self.setContent(_itemHolders[1], _currentItemIndex);

                self.updateCurrItem();

                _shout('afterInit');

                if (!_isFixedPosition) {

                    // On all versions of iOS lower than 8.0, we check size of viewport every second.
                    // 
                    // This is done to detect when Safari top & bottom bars appear, 
                    // as this action doesn't trigger any events (like resize). 
                    // 
                    // On iOS8 they fixed this.
                    // 
                    // 10 Nov 2014: iOS 7 usage ~40%. iOS 8 usage 56%.

                    _updateSizeInterval = setInterval(function() {
                        if (!_numAnimations && !_isDragging && !_isZooming && (_currZoomLevel === self.currItem.initialZoomLevel)) {
                            self.updateSize();
                        }
                    }, 1000);
                }

                framework.addClass(template, 'pswp--visible');
            },

            // Close the gallery, then destroy it
            close: function() {
                if (!_isOpen) {
                    return;
                }

                _isOpen = false;
                _isDestroying = true;
                _shout('close');
                _unbindEvents();

                _showOrHide(self.currItem, null, true, self.destroy);
            },

            // destroys the gallery (unbinds events, cleans up intervals and timeouts to avoid memory leaks)
            destroy: function() {
                _shout('destroy');

                if (_showOrHideTimeout) {
                    clearTimeout(_showOrHideTimeout);
                }

                template.setAttribute('aria-hidden', 'true');
                template.className = _initalClassName;

                if (_updateSizeInterval) {
                    clearInterval(_updateSizeInterval);
                }

                framework.unbind(self.scrollWrap, _downEvents, self);

                // we unbind scroll event at the end, as closing animation may depend on it
                framework.unbind(window, 'scroll', self);

                _stopDragUpdateLoop();

                _stopAllAnimations();

                _listeners = null;
            },

            /**
             * Pan image to position
             * @param {Number} x     
             * @param {Number} y     
             * @param {Boolean} force Will ignore bounds if set to true.
             */
            panTo: function(x, y, force) {
                if (!force) {
                    if (x > _currPanBounds.min.x) {
                        x = _currPanBounds.min.x;
                    } else if (x < _currPanBounds.max.x) {
                        x = _currPanBounds.max.x;
                    }

                    if (y > _currPanBounds.min.y) {
                        y = _currPanBounds.min.y;
                    } else if (y < _currPanBounds.max.y) {
                        y = _currPanBounds.max.y;
                    }
                }

                _panOffset.x = x;
                _panOffset.y = y;
                _applyCurrentZoomPan();
            },

            handleEvent: function(e) {
                e = e || window.event;
                if (_globalEventHandlers[e.type]) {
                    _globalEventHandlers[e.type](e);
                }
            },


            goTo: function(index) {

                index = _getLoopedId(index);

                var diff = index - _currentItemIndex;
                _indexDiff = diff;

                _currentItemIndex = index;
                self.currItem = _getItemAt(_currentItemIndex);
                _currPositionIndex -= diff;

                _moveMainScroll(_slideSize.x * _currPositionIndex);


                _stopAllAnimations();
                _mainScrollAnimating = false;

                self.updateCurrItem();
            },
            next: function() {
                self.goTo(_currentItemIndex + 1);
            },
            prev: function() {
                self.goTo(_currentItemIndex - 1);
            },

            // update current zoom/pan objects
            updateCurrZoomItem: function(emulateSetContent) {
                if (emulateSetContent) {
                    _shout('beforeChange', 0);
                }

                // itemHolder[1] is middle (current) item
                if (_itemHolders[1].el.children.length) {
                    var zoomElement = _itemHolders[1].el.children[0];
                    if (framework.hasClass(zoomElement, 'pswp__zoom-wrap')) {
                        _currZoomElementStyle = zoomElement.style;
                    } else {
                        _currZoomElementStyle = null;
                    }
                } else {
                    _currZoomElementStyle = null;
                }

                _currPanBounds = self.currItem.bounds;
                _startZoomLevel = _currZoomLevel = self.currItem.initialZoomLevel;

                _panOffset.x = _currPanBounds.center.x;
                _panOffset.y = _currPanBounds.center.y;

                if (emulateSetContent) {
                    _shout('afterChange');
                }
            },


            invalidateCurrItems: function() {
                _itemsNeedUpdate = true;
                for (var i = 0; i < NUM_HOLDERS; i++) {
                    if (_itemHolders[i].item) {
                        _itemHolders[i].item.needsUpdate = true;
                    }
                }
            },

            updateCurrItem: function(beforeAnimation) {

                if (_indexDiff === 0) {
                    return;
                }

                var diffAbs = Math.abs(_indexDiff),
                    tempHolder;

                if (beforeAnimation && diffAbs < 2) {
                    return;
                }


                self.currItem = _getItemAt(_currentItemIndex);
                _renderMaxResolution = false;

                _shout('beforeChange', _indexDiff);

                if (diffAbs >= NUM_HOLDERS) {
                    _containerShiftIndex += _indexDiff + (_indexDiff > 0 ? -NUM_HOLDERS : NUM_HOLDERS);
                    diffAbs = NUM_HOLDERS;
                }
                for (var i = 0; i < diffAbs; i++) {
                    if (_indexDiff > 0) {
                        tempHolder = _itemHolders.shift();
                        _itemHolders[NUM_HOLDERS - 1] = tempHolder; // move first to last

                        _containerShiftIndex++;
                        _setTranslateX((_containerShiftIndex + 2) * _slideSize.x, tempHolder.el.style);
                        self.setContent(tempHolder, _currentItemIndex - diffAbs + i + 1 + 1);
                    } else {
                        tempHolder = _itemHolders.pop();
                        _itemHolders.unshift(tempHolder); // move last to first

                        _containerShiftIndex--;
                        _setTranslateX(_containerShiftIndex * _slideSize.x, tempHolder.el.style);
                        self.setContent(tempHolder, _currentItemIndex + diffAbs - i - 1 - 1);
                    }

                }

                // reset zoom/pan on previous item
                if (_currZoomElementStyle && Math.abs(_indexDiff) === 1) {

                    var prevItem = _getItemAt(_prevItemIndex);
                    if (prevItem.initialZoomLevel !== _currZoomLevel) {
                        _calculateItemSize(prevItem, _viewportSize);
                        _setImageSize(prevItem);
                        _applyZoomPanToItem(prevItem);
                    }

                }

                // reset diff after update
                _indexDiff = 0;

                self.updateCurrZoomItem();

                _prevItemIndex = _currentItemIndex;

                _shout('afterChange');

            },



            updateSize: function(force) {

                if (!_isFixedPosition && _options.modal) {
                    var windowScrollY = framework.getScrollY();
                    if (_currentWindowScrollY !== windowScrollY) {
                        template.style.top = windowScrollY + 'px';
                        _currentWindowScrollY = windowScrollY;
                    }
                    if (!force && _windowVisibleSize.x === window.innerWidth && _windowVisibleSize.y === window.innerHeight) {
                        return;
                    }
                    _windowVisibleSize.x = window.innerWidth;
                    _windowVisibleSize.y = window.innerHeight;

                    //template.style.width = _windowVisibleSize.x + 'px';
                    template.style.height = _windowVisibleSize.y + 'px';
                }



                _viewportSize.x = self.scrollWrap.clientWidth;
                _viewportSize.y = self.scrollWrap.clientHeight;

                _updatePageScrollOffset();

                _slideSize.x = _viewportSize.x + Math.round(_viewportSize.x * _options.spacing);
                _slideSize.y = _viewportSize.y;

                _moveMainScroll(_slideSize.x * _currPositionIndex);

                _shout('beforeResize'); // even may be used for example to switch image sources


                // don't re-calculate size on inital size update
                if (_containerShiftIndex !== undefined) {

                    var holder,
                        item,
                        hIndex;

                    for (var i = 0; i < NUM_HOLDERS; i++) {
                        holder = _itemHolders[i];
                        _setTranslateX((i + _containerShiftIndex) * _slideSize.x, holder.el.style);

                        hIndex = _currentItemIndex + i - 1;

                        if (_options.loop && _getNumItems() > 2) {
                            hIndex = _getLoopedId(hIndex);
                        }

                        // update zoom level on items and refresh source (if needsUpdate)
                        item = _getItemAt(hIndex);

                        // re-render gallery item if `needsUpdate`,
                        // or doesn't have `bounds` (entirely new slide object)
                        if (item && (_itemsNeedUpdate || item.needsUpdate || !item.bounds)) {

                            self.cleanSlide(item);

                            self.setContent(holder, hIndex);

                            // if "center" slide
                            if (i === 1) {
                                self.currItem = item;
                                self.updateCurrZoomItem(true);
                            }

                            item.needsUpdate = false;

                        } else if (holder.index === -1 && hIndex >= 0) {
                            // add content first time
                            self.setContent(holder, hIndex);
                        }
                        if (item && item.container) {
                            _calculateItemSize(item, _viewportSize);
                            _setImageSize(item);
                            _applyZoomPanToItem(item);
                        }

                    }
                    _itemsNeedUpdate = false;
                }

                _startZoomLevel = _currZoomLevel = self.currItem.initialZoomLevel;
                _currPanBounds = self.currItem.bounds;

                if (_currPanBounds) {
                    _panOffset.x = _currPanBounds.center.x;
                    _panOffset.y = _currPanBounds.center.y;
                    _applyCurrentZoomPan(true);
                }

                _shout('resize');
            },

            // Zoom current item to
            zoomTo: function(destZoomLevel, centerPoint, speed, easingFn, updateFn) {
                /*
                    if(destZoomLevel === 'fit') {
                        destZoomLevel = self.currItem.fitRatio;
                    } else if(destZoomLevel === 'fill') {
                        destZoomLevel = self.currItem.fillRatio;
                    }
                */

                if (centerPoint) {
                    _startZoomLevel = _currZoomLevel;
                    _midZoomPoint.x = Math.abs(centerPoint.x) - _panOffset.x;
                    _midZoomPoint.y = Math.abs(centerPoint.y) - _panOffset.y;
                    _equalizePoints(_startPanOffset, _panOffset);
                }

                var destPanBounds = _calculatePanBounds(destZoomLevel, false),
                    destPanOffset = {};

                _modifyDestPanOffset('x', destPanBounds, destPanOffset, destZoomLevel);
                _modifyDestPanOffset('y', destPanBounds, destPanOffset, destZoomLevel);

                var initialZoomLevel = _currZoomLevel;
                var initialPanOffset = {
                    x: _panOffset.x,
                    y: _panOffset.y
                };

                _roundPoint(destPanOffset);

                var onUpdate = function(now) {
                    if (now === 1) {
                        _currZoomLevel = destZoomLevel;
                        _panOffset.x = destPanOffset.x;
                        _panOffset.y = destPanOffset.y;
                    } else {
                        _currZoomLevel = (destZoomLevel - initialZoomLevel) * now + initialZoomLevel;
                        _panOffset.x = (destPanOffset.x - initialPanOffset.x) * now + initialPanOffset.x;
                        _panOffset.y = (destPanOffset.y - initialPanOffset.y) * now + initialPanOffset.y;
                    }

                    if (updateFn) {
                        updateFn(now);
                    }

                    _applyCurrentZoomPan(now === 1);
                };

                if (speed) {
                    _animateProp('customZoomTo', 0, 1, speed, easingFn || framework.easing.sine.inOut, onUpdate);
                } else {
                    onUpdate(1);
                }
            }


        };


        /*>>core*/

        /*>>gestures*/
        /**
         * Mouse/touch/pointer event handlers.
         * 
         * separated from @core.js for readability
         */

        var MIN_SWIPE_DISTANCE = 30,
            DIRECTION_CHECK_OFFSET = 10; // amount of pixels to drag to determine direction of swipe

        var _gestureStartTime,
            _gestureCheckSpeedTime,

            // pool of objects that are used during dragging of zooming
            p = {}, // first point
            p2 = {}, // second point (for zoom gesture)
            delta = {},
            _currPoint = {},
            _startPoint = {},
            _currPointers = [],
            _startMainScrollPos = {},
            _releaseAnimData,
            _posPoints = [], // array of points during dragging, used to determine type of gesture
            _tempPoint = {},

            _isZoomingIn,
            _verticalDragInitiated,
            _oldAndroidTouchEndTimeout,
            _currZoomedItemIndex = 0,
            _centerPoint = _getEmptyPoint(),
            _lastReleaseTime = 0,
            _isDragging, // at least one pointer is down
            _isMultitouch, // at least two _pointers are down
            _zoomStarted, // zoom level changed during zoom gesture
            _moved,
            _dragAnimFrame,
            _mainScrollShifted,
            _currentPoints, // array of current touch points
            _isZooming,
            _currPointsDistance,
            _startPointsDistance,
            _currPanBounds,
            _mainScrollPos = _getEmptyPoint(),
            _currZoomElementStyle,
            _mainScrollAnimating, // true, if animation after swipe gesture is running
            _midZoomPoint = _getEmptyPoint(),
            _currCenterPoint = _getEmptyPoint(),
            _direction,
            _isFirstMove,
            _opacityChanged,
            _bgOpacity,
            _wasOverInitialZoom,

            _isEqualPoints = function(p1, p2) {
                return p1.x === p2.x && p1.y === p2.y;
            },
            _isNearbyPoints = function(touch0, touch1) {
                return Math.abs(touch0.x - touch1.x) < DOUBLE_TAP_RADIUS && Math.abs(touch0.y - touch1.y) < DOUBLE_TAP_RADIUS;
            },
            _calculatePointsDistance = function(p1, p2) {
                _tempPoint.x = Math.abs(p1.x - p2.x);
                _tempPoint.y = Math.abs(p1.y - p2.y);
                return Math.sqrt(_tempPoint.x * _tempPoint.x + _tempPoint.y * _tempPoint.y);
            },
            _stopDragUpdateLoop = function() {
                if (_dragAnimFrame) {
                    _cancelAF(_dragAnimFrame);
                    _dragAnimFrame = null;
                }
            },
            _dragUpdateLoop = function() {
                if (_isDragging) {
                    _dragAnimFrame = _requestAF(_dragUpdateLoop);
                    _renderMovement();
                }
            },
            _canPan = function() {
                return !(_options.scaleMode === 'fit' && _currZoomLevel === self.currItem.initialZoomLevel);
            },

            // find the closest parent DOM element
            _closestElement = function(el, fn) {
                if (!el || el === document) {
                    return false;
                }

                // don't search elements above pswp__scroll-wrap
                if (el.getAttribute('class') && el.getAttribute('class').indexOf('pswp__scroll-wrap') > -1) {
                    return false;
                }

                if (fn(el)) {
                    return el;
                }

                return _closestElement(el.parentNode, fn);
            },

            _preventObj = {},
            _preventDefaultEventBehaviour = function(e, isDown) {
                _preventObj.prevent = !_closestElement(e.target, _options.isClickableElement);

                _shout('preventDragEvent', e, isDown, _preventObj);
                return _preventObj.prevent;

            },
            _convertTouchToPoint = function(touch, p) {
                p.x = touch.pageX;
                p.y = touch.pageY;
                p.id = touch.identifier;
                return p;
            },
            _findCenterOfPoints = function(p1, p2, pCenter) {
                pCenter.x = (p1.x + p2.x) * 0.5;
                pCenter.y = (p1.y + p2.y) * 0.5;
            },
            _pushPosPoint = function(time, x, y) {
                if (time - _gestureCheckSpeedTime > 50) {
                    var o = _posPoints.length > 2 ? _posPoints.shift() : {};
                    o.x = x;
                    o.y = y;
                    _posPoints.push(o);
                    _gestureCheckSpeedTime = time;
                }
            },

            _calculateVerticalDragOpacityRatio = function() {
                var yOffset = _panOffset.y - self.currItem.initialPosition.y; // difference between initial and current position
                return 1 - Math.abs(yOffset / (_viewportSize.y / 2));
            },


            // points pool, reused during touch events
            _ePoint1 = {},
            _ePoint2 = {},
            _tempPointsArr = [],
            _tempCounter,
            _getTouchPoints = function(e) {
                // clean up previous points, without recreating array
                while (_tempPointsArr.length > 0) {
                    _tempPointsArr.pop();
                }

                if (!_pointerEventEnabled) {
                    if (e.type.indexOf('touch') > -1) {

                        if (e.touches && e.touches.length > 0) {
                            _tempPointsArr[0] = _convertTouchToPoint(e.touches[0], _ePoint1);
                            if (e.touches.length > 1) {
                                _tempPointsArr[1] = _convertTouchToPoint(e.touches[1], _ePoint2);
                            }
                        }

                    } else {
                        _ePoint1.x = e.pageX;
                        _ePoint1.y = e.pageY;
                        _ePoint1.id = '';
                        _tempPointsArr[0] = _ePoint1; //_ePoint1;
                    }
                } else {
                    _tempCounter = 0;
                    // we can use forEach, as pointer events are supported only in modern browsers
                    _currPointers.forEach(function(p) {
                        if (_tempCounter === 0) {
                            _tempPointsArr[0] = p;
                        } else if (_tempCounter === 1) {
                            _tempPointsArr[1] = p;
                        }
                        _tempCounter++;

                    });
                }
                return _tempPointsArr;
            },

            _panOrMoveMainScroll = function(axis, delta) {

                var panFriction,
                    overDiff = 0,
                    newOffset = _panOffset[axis] + delta[axis],
                    startOverDiff,
                    dir = delta[axis] > 0,
                    newMainScrollPosition = _mainScrollPos.x + delta.x,
                    mainScrollDiff = _mainScrollPos.x - _startMainScrollPos.x,
                    newPanPos,
                    newMainScrollPos;

                // calculate fdistance over the bounds and friction
                if (newOffset > _currPanBounds.min[axis] || newOffset < _currPanBounds.max[axis]) {
                    panFriction = _options.panEndFriction;
                    // Linear increasing of friction, so at 1/4 of viewport it's at max value. 
                    // Looks not as nice as was expected. Left for history.
                    // panFriction = (1 - (_panOffset[axis] + delta[axis] + panBounds.min[axis]) / (_viewportSize[axis] / 4) );
                } else {
                    panFriction = 1;
                }

                newOffset = _panOffset[axis] + delta[axis] * panFriction;

                // move main scroll or start panning
                if (_options.allowPanToNext || _currZoomLevel === self.currItem.initialZoomLevel) {


                    if (!_currZoomElementStyle) {

                        newMainScrollPos = newMainScrollPosition;

                    } else if (_direction === 'h' && axis === 'x' && !_zoomStarted) {

                        if (dir) {
                            if (newOffset > _currPanBounds.min[axis]) {
                                panFriction = _options.panEndFriction;
                                overDiff = _currPanBounds.min[axis] - newOffset;
                                startOverDiff = _currPanBounds.min[axis] - _startPanOffset[axis];
                            }

                            // drag right
                            if ((startOverDiff <= 0 || mainScrollDiff < 0) && _getNumItems() > 1) {
                                newMainScrollPos = newMainScrollPosition;
                                if (mainScrollDiff < 0 && newMainScrollPosition > _startMainScrollPos.x) {
                                    newMainScrollPos = _startMainScrollPos.x;
                                }
                            } else {
                                if (_currPanBounds.min.x !== _currPanBounds.max.x) {
                                    newPanPos = newOffset;
                                }

                            }

                        } else {

                            if (newOffset < _currPanBounds.max[axis]) {
                                panFriction = _options.panEndFriction;
                                overDiff = newOffset - _currPanBounds.max[axis];
                                startOverDiff = _startPanOffset[axis] - _currPanBounds.max[axis];
                            }

                            if ((startOverDiff <= 0 || mainScrollDiff > 0) && _getNumItems() > 1) {
                                newMainScrollPos = newMainScrollPosition;

                                if (mainScrollDiff > 0 && newMainScrollPosition < _startMainScrollPos.x) {
                                    newMainScrollPos = _startMainScrollPos.x;
                                }

                            } else {
                                if (_currPanBounds.min.x !== _currPanBounds.max.x) {
                                    newPanPos = newOffset;
                                }
                            }

                        }


                        //
                    }

                    if (axis === 'x') {

                        if (newMainScrollPos !== undefined) {
                            _moveMainScroll(newMainScrollPos, true);
                            if (newMainScrollPos === _startMainScrollPos.x) {
                                _mainScrollShifted = false;
                            } else {
                                _mainScrollShifted = true;
                            }
                        }

                        if (_currPanBounds.min.x !== _currPanBounds.max.x) {
                            if (newPanPos !== undefined) {
                                _panOffset.x = newPanPos;
                            } else if (!_mainScrollShifted) {
                                _panOffset.x += delta.x * panFriction;
                            }
                        }

                        return newMainScrollPos !== undefined;
                    }

                }

                if (!_mainScrollAnimating) {

                    if (!_mainScrollShifted) {
                        if (_currZoomLevel > self.currItem.fitRatio) {
                            _panOffset[axis] += delta[axis] * panFriction;

                        }
                    }


                }

            },

            // Pointerdown/touchstart/mousedown handler
            _onDragStart = function(e) {

                // Allow dragging only via left mouse button.
                // As this handler is not added in IE8 - we ignore e.which
                // 
                // http://www.quirksmode.org/js/events_properties.html
                // https://developer.mozilla.org/en-US/docs/Web/API/event.button
                if (e.type === 'mousedown' && e.button > 0) {
                    return;
                }

                if (_initialZoomRunning) {
                    e.preventDefault();
                    return;
                }

                if (_oldAndroidTouchEndTimeout && e.type === 'mousedown') {
                    return;
                }

                if (_preventDefaultEventBehaviour(e, true)) {
                    e.preventDefault();
                }



                _shout('pointerDown');

                if (_pointerEventEnabled) {
                    var pointerIndex = framework.arraySearch(_currPointers, e.pointerId, 'id');
                    if (pointerIndex < 0) {
                        pointerIndex = _currPointers.length;
                    }
                    _currPointers[pointerIndex] = { x: e.pageX, y: e.pageY, id: e.pointerId };
                }



                var startPointsList = _getTouchPoints(e),
                    numPoints = startPointsList.length;

                _currentPoints = null;

                _stopAllAnimations();

                // init drag
                if (!_isDragging || numPoints === 1) {



                    _isDragging = _isFirstMove = true;
                    framework.bind(window, _upMoveEvents, self);

                    _isZoomingIn =
                        _wasOverInitialZoom =
                        _opacityChanged =
                        _verticalDragInitiated =
                        _mainScrollShifted =
                        _moved =
                        _isMultitouch =
                        _zoomStarted = false;

                    _direction = null;

                    _shout('firstTouchStart', startPointsList);

                    _equalizePoints(_startPanOffset, _panOffset);

                    _currPanDist.x = _currPanDist.y = 0;
                    _equalizePoints(_currPoint, startPointsList[0]);
                    _equalizePoints(_startPoint, _currPoint);

                    //_equalizePoints(_startMainScrollPos, _mainScrollPos);
                    _startMainScrollPos.x = _slideSize.x * _currPositionIndex;

                    _posPoints = [{
                        x: _currPoint.x,
                        y: _currPoint.y
                    }];

                    _gestureCheckSpeedTime = _gestureStartTime = _getCurrentTime();

                    //_mainScrollAnimationEnd(true);
                    _calculatePanBounds(_currZoomLevel, true);

                    // Start rendering
                    _stopDragUpdateLoop();
                    _dragUpdateLoop();

                }

                // init zoom
                if (!_isZooming && numPoints > 1 && !_mainScrollAnimating && !_mainScrollShifted) {
                    _startZoomLevel = _currZoomLevel;
                    _zoomStarted = false; // true if zoom changed at least once

                    _isZooming = _isMultitouch = true;
                    _currPanDist.y = _currPanDist.x = 0;

                    _equalizePoints(_startPanOffset, _panOffset);

                    _equalizePoints(p, startPointsList[0]);
                    _equalizePoints(p2, startPointsList[1]);

                    _findCenterOfPoints(p, p2, _currCenterPoint);

                    _midZoomPoint.x = Math.abs(_currCenterPoint.x) - _panOffset.x;
                    _midZoomPoint.y = Math.abs(_currCenterPoint.y) - _panOffset.y;
                    _currPointsDistance = _startPointsDistance = _calculatePointsDistance(p, p2);
                }


            },

            // Pointermove/touchmove/mousemove handler
            _onDragMove = function(e) {

                e.preventDefault();

                if (_pointerEventEnabled) {
                    var pointerIndex = framework.arraySearch(_currPointers, e.pointerId, 'id');
                    if (pointerIndex > -1) {
                        var p = _currPointers[pointerIndex];
                        p.x = e.pageX;
                        p.y = e.pageY;
                    }
                }

                if (_isDragging) {
                    var touchesList = _getTouchPoints(e);
                    if (!_direction && !_moved && !_isZooming) {

                        if (_mainScrollPos.x !== _slideSize.x * _currPositionIndex) {
                            // if main scroll position is shifted – direction is always horizontal
                            _direction = 'h';
                        } else {
                            var diff = Math.abs(touchesList[0].x - _currPoint.x) - Math.abs(touchesList[0].y - _currPoint.y);
                            // check the direction of movement
                            if (Math.abs(diff) >= DIRECTION_CHECK_OFFSET) {
                                _direction = diff > 0 ? 'h' : 'v';
                                _currentPoints = touchesList;
                            }
                        }

                    } else {
                        _currentPoints = touchesList;
                    }
                }
            },
            // 
            _renderMovement = function() {

                if (!_currentPoints) {
                    return;
                }

                var numPoints = _currentPoints.length;

                if (numPoints === 0) {
                    return;
                }

                _equalizePoints(p, _currentPoints[0]);

                delta.x = p.x - _currPoint.x;
                delta.y = p.y - _currPoint.y;

                if (_isZooming && numPoints > 1) {
                    // Handle behaviour for more than 1 point

                    _currPoint.x = p.x;
                    _currPoint.y = p.y;

                    // check if one of two points changed
                    if (!delta.x && !delta.y && _isEqualPoints(_currentPoints[1], p2)) {
                        return;
                    }

                    _equalizePoints(p2, _currentPoints[1]);


                    if (!_zoomStarted) {
                        _zoomStarted = true;
                        _shout('zoomGestureStarted');
                    }

                    // Distance between two points
                    var pointsDistance = _calculatePointsDistance(p, p2);

                    var zoomLevel = _calculateZoomLevel(pointsDistance);

                    // slightly over the of initial zoom level
                    if (zoomLevel > self.currItem.initialZoomLevel + self.currItem.initialZoomLevel / 15) {
                        _wasOverInitialZoom = true;
                    }

                    // Apply the friction if zoom level is out of the bounds
                    var zoomFriction = 1,
                        minZoomLevel = _getMinZoomLevel(),
                        maxZoomLevel = _getMaxZoomLevel();

                    if (zoomLevel < minZoomLevel) {

                        if (_options.pinchToClose && !_wasOverInitialZoom && _startZoomLevel <= self.currItem.initialZoomLevel) {
                            // fade out background if zooming out
                            var minusDiff = minZoomLevel - zoomLevel;
                            var percent = 1 - minusDiff / (minZoomLevel / 1.2);

                            _applyBgOpacity(percent);
                            _shout('onPinchClose', percent);
                            _opacityChanged = true;
                        } else {
                            zoomFriction = (minZoomLevel - zoomLevel) / minZoomLevel;
                            if (zoomFriction > 1) {
                                zoomFriction = 1;
                            }
                            zoomLevel = minZoomLevel - zoomFriction * (minZoomLevel / 3);
                        }

                    } else if (zoomLevel > maxZoomLevel) {
                        // 1.5 - extra zoom level above the max. E.g. if max is x6, real max 6 + 1.5 = 7.5
                        zoomFriction = (zoomLevel - maxZoomLevel) / (minZoomLevel * 6);
                        if (zoomFriction > 1) {
                            zoomFriction = 1;
                        }
                        zoomLevel = maxZoomLevel + zoomFriction * minZoomLevel;
                    }

                    if (zoomFriction < 0) {
                        zoomFriction = 0;
                    }

                    // distance between touch points after friction is applied
                    _currPointsDistance = pointsDistance;

                    // _centerPoint - The point in the middle of two pointers
                    _findCenterOfPoints(p, p2, _centerPoint);

                    // paning with two pointers pressed
                    _currPanDist.x += _centerPoint.x - _currCenterPoint.x;
                    _currPanDist.y += _centerPoint.y - _currCenterPoint.y;
                    _equalizePoints(_currCenterPoint, _centerPoint);

                    _panOffset.x = _calculatePanOffset('x', zoomLevel);
                    _panOffset.y = _calculatePanOffset('y', zoomLevel);

                    _isZoomingIn = zoomLevel > _currZoomLevel;
                    _currZoomLevel = zoomLevel;
                    _applyCurrentZoomPan();

                } else {

                    // handle behaviour for one point (dragging or panning)

                    if (!_direction) {
                        return;
                    }

                    if (_isFirstMove) {
                        _isFirstMove = false;

                        // subtract drag distance that was used during the detection direction  

                        if (Math.abs(delta.x) >= DIRECTION_CHECK_OFFSET) {
                            delta.x -= _currentPoints[0].x - _startPoint.x;
                        }

                        if (Math.abs(delta.y) >= DIRECTION_CHECK_OFFSET) {
                            delta.y -= _currentPoints[0].y - _startPoint.y;
                        }
                    }

                    _currPoint.x = p.x;
                    _currPoint.y = p.y;

                    // do nothing if pointers position hasn't changed
                    if (delta.x === 0 && delta.y === 0) {
                        return;
                    }

                    if (_direction === 'v' && _options.closeOnVerticalDrag) {
                        if (!_canPan()) {
                            _currPanDist.y += delta.y;
                            _panOffset.y += delta.y;

                            var opacityRatio = _calculateVerticalDragOpacityRatio();

                            _verticalDragInitiated = true;
                            _shout('onVerticalDrag', opacityRatio);

                            _applyBgOpacity(opacityRatio);
                            _applyCurrentZoomPan();
                            return;
                        }
                    }

                    _pushPosPoint(_getCurrentTime(), p.x, p.y);

                    _moved = true;
                    _currPanBounds = self.currItem.bounds;

                    var mainScrollChanged = _panOrMoveMainScroll('x', delta);
                    if (!mainScrollChanged) {
                        _panOrMoveMainScroll('y', delta);

                        _roundPoint(_panOffset);
                        _applyCurrentZoomPan();
                    }

                }

            },

            // Pointerup/pointercancel/touchend/touchcancel/mouseup event handler
            _onDragRelease = function(e) {

                if (_features.isOldAndroid) {

                    if (_oldAndroidTouchEndTimeout && e.type === 'mouseup') {
                        return;
                    }

                    // on Android (v4.1, 4.2, 4.3 & possibly older) 
                    // ghost mousedown/up event isn't preventable via e.preventDefault,
                    // which causes fake mousedown event
                    // so we block mousedown/up for 600ms
                    if (e.type.indexOf('touch') > -1) {
                        clearTimeout(_oldAndroidTouchEndTimeout);
                        _oldAndroidTouchEndTimeout = setTimeout(function() {
                            _oldAndroidTouchEndTimeout = 0;
                        }, 600);
                    }

                }

                _shout('pointerUp');

                if (_preventDefaultEventBehaviour(e, false)) {
                    e.preventDefault();
                }

                var releasePoint;

                if (_pointerEventEnabled) {
                    var pointerIndex = framework.arraySearch(_currPointers, e.pointerId, 'id');

                    if (pointerIndex > -1) {
                        releasePoint = _currPointers.splice(pointerIndex, 1)[0];

                        if (navigator.pointerEnabled) {
                            releasePoint.type = e.pointerType || 'mouse';
                        } else {
                            var MSPOINTER_TYPES = {
                                4: 'mouse', // event.MSPOINTER_TYPE_MOUSE
                                2: 'touch', // event.MSPOINTER_TYPE_TOUCH 
                                3: 'pen' // event.MSPOINTER_TYPE_PEN
                            };
                            releasePoint.type = MSPOINTER_TYPES[e.pointerType];

                            if (!releasePoint.type) {
                                releasePoint.type = e.pointerType || 'mouse';
                            }
                        }

                    }
                }

                var touchList = _getTouchPoints(e),
                    gestureType,
                    numPoints = touchList.length;

                if (e.type === 'mouseup') {
                    numPoints = 0;
                }

                // Do nothing if there were 3 touch points or more
                if (numPoints === 2) {
                    _currentPoints = null;
                    return true;
                }

                // if second pointer released
                if (numPoints === 1) {
                    _equalizePoints(_startPoint, touchList[0]);
                }


                // pointer hasn't moved, send "tap release" point
                if (numPoints === 0 && !_direction && !_mainScrollAnimating) {
                    if (!releasePoint) {
                        if (e.type === 'mouseup') {
                            releasePoint = { x: e.pageX, y: e.pageY, type: 'mouse' };
                        } else if (e.changedTouches && e.changedTouches[0]) {
                            releasePoint = { x: e.changedTouches[0].pageX, y: e.changedTouches[0].pageY, type: 'touch' };
                        }
                    }

                    _shout('touchRelease', e, releasePoint);
                }

                // Difference in time between releasing of two last touch points (zoom gesture)
                var releaseTimeDiff = -1;

                // Gesture completed, no pointers left
                if (numPoints === 0) {
                    _isDragging = false;
                    framework.unbind(window, _upMoveEvents, self);

                    _stopDragUpdateLoop();

                    if (_isZooming) {
                        // Two points released at the same time
                        releaseTimeDiff = 0;
                    } else if (_lastReleaseTime !== -1) {
                        releaseTimeDiff = _getCurrentTime() - _lastReleaseTime;
                    }
                }
                _lastReleaseTime = numPoints === 1 ? _getCurrentTime() : -1;

                if (releaseTimeDiff !== -1 && releaseTimeDiff < 150) {
                    gestureType = 'zoom';
                } else {
                    gestureType = 'swipe';
                }

                if (_isZooming && numPoints < 2) {
                    _isZooming = false;

                    // Only second point released
                    if (numPoints === 1) {
                        gestureType = 'zoomPointerUp';
                    }
                    _shout('zoomGestureEnded');
                }

                _currentPoints = null;
                if (!_moved && !_zoomStarted && !_mainScrollAnimating && !_verticalDragInitiated) {
                    // nothing to animate
                    return;
                }

                _stopAllAnimations();


                if (!_releaseAnimData) {
                    _releaseAnimData = _initDragReleaseAnimationData();
                }

                _releaseAnimData.calculateSwipeSpeed('x');


                if (_verticalDragInitiated) {

                    var opacityRatio = _calculateVerticalDragOpacityRatio();

                    //if (opacityRatio < _options.verticalDragRange) {
                    //self.close();
                    //} else {
                    var initalPanY = _panOffset.y,
                        initialBgOpacity = _bgOpacity;

                    _animateProp('verticalDrag', 0, 1, 300, framework.easing.cubic.out, function(now) {

                        _panOffset.y = (self.currItem.initialPosition.y - initalPanY) * now + initalPanY;

                        _applyBgOpacity((1 - initialBgOpacity) * now + initialBgOpacity);
                        _applyCurrentZoomPan();
                    });

                    _shout('onVerticalDrag', 1);
                    //}

                    return;
                }


                // main scroll 
                if ((_mainScrollShifted || _mainScrollAnimating) && numPoints === 0) {
                    var itemChanged = _finishSwipeMainScrollGesture(gestureType, _releaseAnimData);
                    if (itemChanged) {
                        return;
                    }
                    gestureType = 'zoomPointerUp';
                }

                // prevent zoom/pan animation when main scroll animation runs
                if (_mainScrollAnimating) {
                    return;
                }

                // Complete simple zoom gesture (reset zoom level if it's out of the bounds)  
                if (gestureType !== 'swipe') {
                    _completeZoomGesture();
                    return;
                }

                // Complete pan gesture if main scroll is not shifted, and it's possible to pan current image
                if (!_mainScrollShifted && _currZoomLevel > self.currItem.fitRatio) {
                    _completePanGesture(_releaseAnimData);
                }
            },


            // Returns object with data about gesture
            // It's created only once and then reused
            _initDragReleaseAnimationData = function() {
                // temp local vars
                var lastFlickDuration,
                    tempReleasePos;

                // s = this
                var s = {
                    lastFlickOffset: {},
                    lastFlickDist: {},
                    lastFlickSpeed: {},
                    slowDownRatio: {},
                    slowDownRatioReverse: {},
                    speedDecelerationRatio: {},
                    speedDecelerationRatioAbs: {},
                    distanceOffset: {},
                    backAnimDestination: {},
                    backAnimStarted: {},
                    calculateSwipeSpeed: function(axis) {


                        if (_posPoints.length > 1) {
                            lastFlickDuration = _getCurrentTime() - _gestureCheckSpeedTime + 50;
                            tempReleasePos = _posPoints[_posPoints.length - 2][axis];
                        } else {
                            lastFlickDuration = _getCurrentTime() - _gestureStartTime; // total gesture duration
                            tempReleasePos = _startPoint[axis];
                        }
                        s.lastFlickOffset[axis] = _currPoint[axis] - tempReleasePos;
                        s.lastFlickDist[axis] = Math.abs(s.lastFlickOffset[axis]);
                        if (s.lastFlickDist[axis] > 20) {
                            s.lastFlickSpeed[axis] = s.lastFlickOffset[axis] / lastFlickDuration;
                        } else {
                            s.lastFlickSpeed[axis] = 0;
                        }
                        if (Math.abs(s.lastFlickSpeed[axis]) < 0.1) {
                            s.lastFlickSpeed[axis] = 0;
                        }

                        s.slowDownRatio[axis] = 0.95;
                        s.slowDownRatioReverse[axis] = 1 - s.slowDownRatio[axis];
                        s.speedDecelerationRatio[axis] = 1;
                    },

                    calculateOverBoundsAnimOffset: function(axis, speed) {
                        if (!s.backAnimStarted[axis]) {

                            if (_panOffset[axis] > _currPanBounds.min[axis]) {
                                s.backAnimDestination[axis] = _currPanBounds.min[axis];

                            } else if (_panOffset[axis] < _currPanBounds.max[axis]) {
                                s.backAnimDestination[axis] = _currPanBounds.max[axis];
                            }

                            if (s.backAnimDestination[axis] !== undefined) {
                                s.slowDownRatio[axis] = 0.7;
                                s.slowDownRatioReverse[axis] = 1 - s.slowDownRatio[axis];
                                if (s.speedDecelerationRatioAbs[axis] < 0.05) {

                                    s.lastFlickSpeed[axis] = 0;
                                    s.backAnimStarted[axis] = true;

                                    _animateProp('bounceZoomPan' + axis, _panOffset[axis],
                                        s.backAnimDestination[axis],
                                        speed || 300,
                                        framework.easing.sine.out,
                                        function(pos) {
                                            _panOffset[axis] = pos;
                                            _applyCurrentZoomPan();
                                        }
                                    );

                                }
                            }
                        }
                    },

                    // Reduces the speed by slowDownRatio (per 10ms)
                    calculateAnimOffset: function(axis) {
                        if (!s.backAnimStarted[axis]) {
                            s.speedDecelerationRatio[axis] = s.speedDecelerationRatio[axis] * (s.slowDownRatio[axis] +
                                s.slowDownRatioReverse[axis] -
                                s.slowDownRatioReverse[axis] * s.timeDiff / 10);

                            s.speedDecelerationRatioAbs[axis] = Math.abs(s.lastFlickSpeed[axis] * s.speedDecelerationRatio[axis]);
                            s.distanceOffset[axis] = s.lastFlickSpeed[axis] * s.speedDecelerationRatio[axis] * s.timeDiff;
                            _panOffset[axis] += s.distanceOffset[axis];

                        }
                    },

                    panAnimLoop: function() {
                        if (_animations.zoomPan) {
                            _animations.zoomPan.raf = _requestAF(s.panAnimLoop);

                            s.now = _getCurrentTime();
                            s.timeDiff = s.now - s.lastNow;
                            s.lastNow = s.now;

                            s.calculateAnimOffset('x');
                            s.calculateAnimOffset('y');

                            _applyCurrentZoomPan();

                            s.calculateOverBoundsAnimOffset('x');
                            s.calculateOverBoundsAnimOffset('y');


                            if (s.speedDecelerationRatioAbs.x < 0.05 && s.speedDecelerationRatioAbs.y < 0.05) {

                                // round pan position
                                _panOffset.x = Math.round(_panOffset.x);
                                _panOffset.y = Math.round(_panOffset.y);
                                _applyCurrentZoomPan();

                                _stopAnimation('zoomPan');
                                return;
                            }
                        }

                    }
                };
                return s;
            },

            _completePanGesture = function(animData) {
                // calculate swipe speed for Y axis (paanning)
                animData.calculateSwipeSpeed('y');

                _currPanBounds = self.currItem.bounds;

                animData.backAnimDestination = {};
                animData.backAnimStarted = {};

                // Avoid acceleration animation if speed is too low
                if (Math.abs(animData.lastFlickSpeed.x) <= 0.05 && Math.abs(animData.lastFlickSpeed.y) <= 0.05) {
                    animData.speedDecelerationRatioAbs.x = animData.speedDecelerationRatioAbs.y = 0;

                    // Run pan drag release animation. E.g. if you drag image and release finger without momentum.
                    animData.calculateOverBoundsAnimOffset('x');
                    animData.calculateOverBoundsAnimOffset('y');
                    return true;
                }

                // Animation loop that controls the acceleration after pan gesture ends
                _registerStartAnimation('zoomPan');
                animData.lastNow = _getCurrentTime();
                animData.panAnimLoop();
            },


            _finishSwipeMainScrollGesture = function(gestureType, _releaseAnimData) {
                var itemChanged;
                if (!_mainScrollAnimating) {
                    _currZoomedItemIndex = _currentItemIndex;
                }



                var itemsDiff;

                if (gestureType === 'swipe') {
                    var totalShiftDist = _currPoint.x - _startPoint.x,
                        isFastLastFlick = _releaseAnimData.lastFlickDist.x < 10;

                    // if container is shifted for more than MIN_SWIPE_DISTANCE, 
                    // and last flick gesture was in right direction
                    if (totalShiftDist > MIN_SWIPE_DISTANCE &&
                        (isFastLastFlick || _releaseAnimData.lastFlickOffset.x > 20)) {
                        // go to prev item
                        itemsDiff = -1;
                    } else if (totalShiftDist < -MIN_SWIPE_DISTANCE &&
                        (isFastLastFlick || _releaseAnimData.lastFlickOffset.x < -20)) {
                        // go to next item
                        itemsDiff = 1;
                    }
                }

                var nextCircle;

                if (itemsDiff) {

                    _currentItemIndex += itemsDiff;

                    if (_currentItemIndex < 0) {
                        _currentItemIndex = _options.loop ? _getNumItems() - 1 : 0;
                        nextCircle = true;
                    } else if (_currentItemIndex >= _getNumItems()) {
                        _currentItemIndex = _options.loop ? 0 : _getNumItems() - 1;
                        nextCircle = true;
                    }

                    if (!nextCircle || _options.loop) {
                        _indexDiff += itemsDiff;
                        _currPositionIndex -= itemsDiff;
                        itemChanged = true;
                    }



                }

                var animateToX = _slideSize.x * _currPositionIndex;
                var animateToDist = Math.abs(animateToX - _mainScrollPos.x);
                var finishAnimDuration;


                if (!itemChanged && animateToX > _mainScrollPos.x !== _releaseAnimData.lastFlickSpeed.x > 0) {
                    // "return to current" duration, e.g. when dragging from slide 0 to -1
                    finishAnimDuration = 333;
                } else {
                    finishAnimDuration = Math.abs(_releaseAnimData.lastFlickSpeed.x) > 0 ?
                        animateToDist / Math.abs(_releaseAnimData.lastFlickSpeed.x) :
                        333;

                    finishAnimDuration = Math.min(finishAnimDuration, 400);
                    finishAnimDuration = Math.max(finishAnimDuration, 250);
                }

                if (_currZoomedItemIndex === _currentItemIndex) {
                    itemChanged = false;
                }

                _mainScrollAnimating = true;

                _shout('mainScrollAnimStart');

                _animateProp('mainScroll', _mainScrollPos.x, animateToX, finishAnimDuration, framework.easing.cubic.out,
                    _moveMainScroll,
                    function() {
                        _stopAllAnimations();
                        _mainScrollAnimating = false;
                        _currZoomedItemIndex = -1;

                        if (itemChanged || _currZoomedItemIndex !== _currentItemIndex) {
                            self.updateCurrItem();
                        }

                        _shout('mainScrollAnimComplete');
                    }
                );

                if (itemChanged) {
                    self.updateCurrItem(true);
                }

                return itemChanged;
            },

            _calculateZoomLevel = function(touchesDistance) {
                return 1 / _startPointsDistance * touchesDistance * _startZoomLevel;
            },

            // Resets zoom if it's out of bounds
            _completeZoomGesture = function() {
                var destZoomLevel = _currZoomLevel,
                    minZoomLevel = _getMinZoomLevel(),
                    maxZoomLevel = _getMaxZoomLevel();

                if (_currZoomLevel < minZoomLevel) {
                    destZoomLevel = minZoomLevel;
                } else if (_currZoomLevel > maxZoomLevel) {
                    destZoomLevel = maxZoomLevel;
                }

                var destOpacity = 1,
                    onUpdate,
                    initialOpacity = _bgOpacity;

                if (_opacityChanged && !_isZoomingIn && !_wasOverInitialZoom && _currZoomLevel < minZoomLevel) {
                    //_closedByScroll = true;
                    //self.close();
                    //return true;
                }

                if (_opacityChanged) {
                    onUpdate = function(now) {
                        _applyBgOpacity((destOpacity - initialOpacity) * now + initialOpacity);
                    };
                }

                self.zoomTo(destZoomLevel, 0, 200, framework.easing.cubic.out, onUpdate);
                return true;
            };


        _registerModule('Gestures', {
            publicMethods: {

                initGestures: function() {

                    // helper function that builds touch/pointer/mouse events
                    var addEventNames = function(pref, down, move, up, cancel) {
                        _dragStartEvent = pref + down;
                        _dragMoveEvent = pref + move;
                        _dragEndEvent = pref + up;
                        if (cancel) {
                            _dragCancelEvent = pref + cancel;
                        } else {
                            _dragCancelEvent = '';
                        }
                    };

                    _pointerEventEnabled = _features.pointerEvent;
                    if (_pointerEventEnabled && _features.touch) {
                        // we don't need touch events, if browser supports pointer events
                        _features.touch = false;
                    }

                    if (_pointerEventEnabled) {
                        if (navigator.pointerEnabled) {
                            addEventNames('pointer', 'down', 'move', 'up', 'cancel');
                        } else {
                            // IE10 pointer events are case-sensitive
                            addEventNames('MSPointer', 'Down', 'Move', 'Up', 'Cancel');
                        }
                    } else if (_features.touch) {
                        addEventNames('touch', 'start', 'move', 'end', 'cancel');
                        _likelyTouchDevice = true;
                    } else {
                        addEventNames('mouse', 'down', 'move', 'up');
                    }

                    _upMoveEvents = _dragMoveEvent + ' ' + _dragEndEvent + ' ' + _dragCancelEvent;
                    _downEvents = _dragStartEvent;

                    if (_pointerEventEnabled && !_likelyTouchDevice) {
                        _likelyTouchDevice = (navigator.maxTouchPoints > 1) || (navigator.msMaxTouchPoints > 1);
                    }
                    // make variable public
                    self.likelyTouchDevice = _likelyTouchDevice;

                    _globalEventHandlers[_dragStartEvent] = _onDragStart;
                    _globalEventHandlers[_dragMoveEvent] = _onDragMove;
                    _globalEventHandlers[_dragEndEvent] = _onDragRelease; // the Kraken

                    if (_dragCancelEvent) {
                        _globalEventHandlers[_dragCancelEvent] = _globalEventHandlers[_dragEndEvent];
                    }

                    // Bind mouse events on device with detected hardware touch support, in case it supports multiple types of input.
                    if (_features.touch) {
                        _downEvents += ' mousedown';
                        _upMoveEvents += ' mousemove mouseup';
                        _globalEventHandlers.mousedown = _globalEventHandlers[_dragStartEvent];
                        _globalEventHandlers.mousemove = _globalEventHandlers[_dragMoveEvent];
                        _globalEventHandlers.mouseup = _globalEventHandlers[_dragEndEvent];
                    }

                    if (!_likelyTouchDevice) {
                        // don't allow pan to next slide from zoomed state on Desktop
                        _options.allowPanToNext = false;
                    }
                }

            }
        });


        /*>>gestures*/

        /*>>show-hide-transition*/
        /**
         * show-hide-transition.js:
         *
         * Manages initial opening or closing transition.
         *
         * If you're not planning to use transition for gallery at all,
         * you may set options hideAnimationDuration and showAnimationDuration to 0,
         * and just delete startAnimation function.
         * 
         */


        var _showOrHideTimeout,
            _showOrHide = function(item, img, out, completeFn) {

                if (_showOrHideTimeout) {
                    clearTimeout(_showOrHideTimeout);
                }

                _initialZoomRunning = true;
                _initialContentSet = true;

                // dimensions of small thumbnail {x:,y:,w:}.
                // Height is optional, as calculated based on large image.
                var thumbBounds;
                if (item.initialLayout) {
                    thumbBounds = item.initialLayout;
                    item.initialLayout = null;
                } else {
                    thumbBounds = _options.getThumbBoundsFn && _options.getThumbBoundsFn(_currentItemIndex);
                }

                var duration = out ? _options.hideAnimationDuration : _options.showAnimationDuration;

                var onComplete = function() {
                    _stopAnimation('initialZoom');
                    if (!out) {
                        _applyBgOpacity(1);
                        if (img) {
                            img.style.display = 'block';
                        }
                        framework.addClass(template, 'pswp--animated-in');
                        _shout('initialZoom' + (out ? 'OutEnd' : 'InEnd'));
                    } else {
                        self.template.removeAttribute('style');
                        self.bg.removeAttribute('style');
                    }

                    if (completeFn) {
                        completeFn();
                    }
                    _initialZoomRunning = false;
                };

                // if bounds aren't provided, just open gallery without animation
                if (!duration || !thumbBounds || thumbBounds.x === undefined) {

                    _shout('initialZoom' + (out ? 'Out' : 'In'));

                    _currZoomLevel = item.initialZoomLevel;
                    _equalizePoints(_panOffset, item.initialPosition);
                    _applyCurrentZoomPan();

                    template.style.opacity = out ? 0 : 1;
                    _applyBgOpacity(1);

                    if (duration) {
                        setTimeout(function() {
                            onComplete();
                        }, duration);
                    } else {
                        onComplete();
                    }

                    return;
                }

                var startAnimation = function() {
                    var closeWithRaf = _closedByScroll,
                        fadeEverything = !self.currItem.src || self.currItem.loadError || _options.showHideOpacity;

                    // apply hw-acceleration to image
                    if (item.miniImg) {
                        item.miniImg.style.webkitBackfaceVisibility = 'hidden';
                    }

                    if (!out) {
                        _currZoomLevel = thumbBounds.w / item.w;
                        _panOffset.x = thumbBounds.x;
                        _panOffset.y = thumbBounds.y - _initalWindowScrollY;

                        self[fadeEverything ? 'template' : 'bg'].style.opacity = 0.001;
                        _applyCurrentZoomPan();
                    }

                    _registerStartAnimation('initialZoom');

                    if (out && !closeWithRaf) {
                        framework.removeClass(template, 'pswp--animated-in');
                    }

                    if (fadeEverything) {
                        if (out) {
                            framework[(closeWithRaf ? 'remove' : 'add') + 'Class'](template, 'pswp--animate_opacity');
                        } else {
                            setTimeout(function() {
                                framework.addClass(template, 'pswp--animate_opacity');
                            }, 30);
                        }
                    }

                    _showOrHideTimeout = setTimeout(function() {

                        _shout('initialZoom' + (out ? 'Out' : 'In'));


                        if (!out) {

                            // "in" animation always uses CSS transitions (instead of rAF).
                            // CSS transition work faster here, 
                            // as developer may also want to animate other things, 
                            // like ui on top of sliding area, which can be animated just via CSS

                            _currZoomLevel = item.initialZoomLevel;
                            _equalizePoints(_panOffset, item.initialPosition);
                            _applyCurrentZoomPan();
                            _applyBgOpacity(1);

                            if (fadeEverything) {
                                template.style.opacity = 1;
                            } else {
                                _applyBgOpacity(1);
                            }

                            _showOrHideTimeout = setTimeout(onComplete, duration + 20);
                        } else {

                            // "out" animation uses rAF only when PhotoSwipe is closed by browser scroll, to recalculate position
                            var destZoomLevel = thumbBounds.w / item.w,
                                initialPanOffset = {
                                    x: _panOffset.x,
                                    y: _panOffset.y
                                },
                                initialZoomLevel = _currZoomLevel,
                                initalBgOpacity = _bgOpacity,
                                onUpdate = function(now) {

                                    if (now === 1) {
                                        _currZoomLevel = destZoomLevel;
                                        _panOffset.x = thumbBounds.x;
                                        _panOffset.y = thumbBounds.y - _currentWindowScrollY;
                                    } else {
                                        _currZoomLevel = (destZoomLevel - initialZoomLevel) * now + initialZoomLevel;
                                        _panOffset.x = (thumbBounds.x - initialPanOffset.x) * now + initialPanOffset.x;
                                        _panOffset.y = (thumbBounds.y - _currentWindowScrollY - initialPanOffset.y) * now + initialPanOffset.y;
                                    }

                                    _applyCurrentZoomPan();
                                    if (fadeEverything) {
                                        template.style.opacity = 1 - now;
                                    } else {
                                        _applyBgOpacity(initalBgOpacity - now * initalBgOpacity);
                                    }
                                };

                            if (closeWithRaf) {
                                _animateProp('initialZoom', 0, 1, duration, framework.easing.cubic.out, onUpdate, onComplete);
                            } else {
                                onUpdate(1);
                                _showOrHideTimeout = setTimeout(onComplete, duration + 20);
                            }
                        }

                    }, out ? 25 : 90); // Main purpose of this delay is to give browser time to paint and
                    // create composite layers of PhotoSwipe UI parts (background, controls, caption, arrows).
                    // Which avoids lag at the beginning of scale transition.
                };
                startAnimation();


            };

        /*>>show-hide-transition*/

        /*>>items-controller*/
        /**
         *
         * Controller manages gallery items, their dimensions, and their content.
         * 
         */

        var _items,
            _tempPanAreaSize = {},
            _imagesToAppendPool = [],
            _initialContentSet,
            _initialZoomRunning,
            _controllerDefaultOptions = {
                index: 0,
                errorMsg: '<div class="pswp__error-msg"><a href="%url%" target="_blank">The image</a> could not be loaded.</div>',
                forceProgressiveLoading: false, // TODO
                preload: [1, 1],
                getNumItemsFn: function() {
                    return _items.length;
                },
                getNumItemsOther: function() {
                    var len = 0;
                    for (var i in _items) {
                        if (_items[i].html) {
                            len++;
                        }
                    }
                    return len;
                }
            };


        var _getItemAt,
            _getNumItems,
            _initialIsLoop,
            _getZeroBounds = function() {
                return {
                    center: { x: 0, y: 0 },
                    max: { x: 0, y: 0 },
                    min: { x: 0, y: 0 }
                };
            },
            _calculateSingleItemPanBounds = function(item, realPanElementW, realPanElementH) {
                var bounds = item.bounds;

                // position of element when it's centered
                bounds.center.x = Math.round((_tempPanAreaSize.x - realPanElementW) / 2);
                bounds.center.y = Math.round((_tempPanAreaSize.y - realPanElementH) / 2) + item.vGap.top;

                // maximum pan position
                bounds.max.x = (realPanElementW > _tempPanAreaSize.x) ?
                    Math.round(_tempPanAreaSize.x - realPanElementW) :
                    bounds.center.x;

                bounds.max.y = (realPanElementH > _tempPanAreaSize.y) ?
                    Math.round(_tempPanAreaSize.y - realPanElementH) + item.vGap.top :
                    bounds.center.y;

                // minimum pan position
                bounds.min.x = (realPanElementW > _tempPanAreaSize.x) ? 0 : bounds.center.x;
                bounds.min.y = (realPanElementH > _tempPanAreaSize.y) ? item.vGap.top : bounds.center.y;
            },
            _calculateItemSize = function(item, viewportSize, zoomLevel) {

                if (item.src && !item.loadError) {
                    var isInitial = !zoomLevel;

                    if (isInitial) {
                        if (!item.vGap) {
                            item.vGap = { top: 0, bottom: 0 };
                        }
                        // allows overriding vertical margin for individual items
                        _shout('parseVerticalMargin', item);
                    }


                    _tempPanAreaSize.x = viewportSize.x;
                    _tempPanAreaSize.y = viewportSize.y - item.vGap.top - item.vGap.bottom;

                    if (isInitial) {
                        var hRatio = _tempPanAreaSize.x / item.w;
                        var vRatio = _tempPanAreaSize.y / item.h;

                        item.fitRatio = hRatio < vRatio ? hRatio : vRatio;
                        //item.fillRatio = hRatio > vRatio ? hRatio : vRatio;

                        var scaleMode = _options.scaleMode;

                        if (scaleMode === 'orig') {
                            zoomLevel = 1;
                        } else if (scaleMode === 'fit') {
                            zoomLevel = item.fitRatio;
                        }

                        if (zoomLevel > 1) {
                            zoomLevel = 1;
                        }

                        item.initialZoomLevel = zoomLevel;

                        if (!item.bounds) {
                            // reuse bounds object
                            item.bounds = _getZeroBounds();
                        }
                    }

                    if (!zoomLevel) {
                        return;
                    }

                    _calculateSingleItemPanBounds(item, item.w * zoomLevel, item.h * zoomLevel);

                    if (isInitial && zoomLevel === item.initialZoomLevel) {
                        item.initialPosition = item.bounds.center;
                    }

                    return item.bounds;
                } else {
                    item.w = item.h = 0;
                    item.initialZoomLevel = item.fitRatio = 1;
                    item.bounds = _getZeroBounds();
                    item.initialPosition = item.bounds.center;

                    // if it's not image, we return zero bounds (content is not zoomable)
                    return item.bounds;
                }

            },




            _appendImage = function(index, item, baseDiv, img, preventAnimation, keepPlaceholder) {

                if (item.loadError) {
                    return;
                }

                if (img) {

                    item.imageAppended = true;
                    _setImageSize(item, img, (item === self.currItem && _renderMaxResolution));

                    baseDiv.appendChild(img);

                    if (keepPlaceholder) {
                        setTimeout(function() {
                            if (item && item.loaded && item.placeholder) {
                                item.placeholder.style.display = 'none';
                                item.placeholder = null;
                            }
                        }, 500);
                    }
                }
            },



            _preloadImage = function(item) {
                item.loading = true;
                item.loaded = false;
                var img = item.img = framework.createEl('pswp__img', 'img');
                var onComplete = function() {
                    item.loading = false;
                    item.loaded = true;

                    if (item.loadComplete) {
                        item.loadComplete(item);
                    } else {
                        item.img = null; // no need to store image object
                    }
                    img.onload = img.onerror = null;
                    img = null;
                };
                img.onload = onComplete;
                img.onerror = function() {
                    item.loadError = true;
                    onComplete();
                };

                img.src = item.src; // + '?a=' + Math.random();

                return img;
            },
            _checkForError = function(item, cleanUp) {
                if (item.src && item.loadError && item.container) {

                    if (cleanUp) {
                        item.container.innerHTML = '';
                    }

                    item.container.innerHTML = _options.errorMsg.replace('%url%', item.src);
                    return true;

                }
            },
            _setImageSize = function(item, img, maxRes) {
                if (!item.src) {
                    return;
                }

                if (!img) {
                    img = item.container.lastChild;
                }

                var w = maxRes ? item.w : Math.round(item.w * item.fitRatio),
                    h = maxRes ? item.h : Math.round(item.h * item.fitRatio);

                if (item.placeholder && !item.loaded) {
                    item.placeholder.style.width = w + 'px';
                    item.placeholder.style.height = h + 'px';
                }

                img.style.width = w + 'px';
                img.style.height = h + 'px';
            },
            _appendImagesPool = function() {

                if (_imagesToAppendPool.length) {
                    var poolItem;

                    for (var i = 0; i < _imagesToAppendPool.length; i++) {
                        poolItem = _imagesToAppendPool[i];
                        if (poolItem.holder.index === poolItem.index) {
                            _appendImage(poolItem.index, poolItem.item, poolItem.baseDiv, poolItem.img, false, poolItem.clearPlaceholder);
                        }
                    }
                    _imagesToAppendPool = [];
                }
            };



        _registerModule('Controller', {

            publicMethods: {

                lazyLoadItem: function(index) {
                    index = _getLoopedId(index);
                    var item = _getItemAt(index);

                    if (!item || ((item.loaded || item.loading) && !_itemsNeedUpdate)) {
                        return;
                    }

                    _shout('gettingData', index, item);

                    if (!item.src) {
                        return;
                    }

                    _preloadImage(item);
                },
                initController: function() {
                    framework.extend(_options, _controllerDefaultOptions, true);
                    self.items = _items = items;
                    _getItemAt = self.getItemAt;
                    _getNumItems = _options.getNumItemsFn; //self.getNumItems;
                    _initialIsLoop = _options.loop;
                    if (_getNumItems() < 3) {
                        _options.loop = false; // disable loop if less then 3 items
                    }

                    _listen('beforeChange', function(diff) {
                        var p = _options.preload,
                            isNext = diff === null ? true : (diff >= 0),
                            preloadBefore = Math.min(p[0], _getNumItems()),
                            preloadAfter = Math.min(p[1], _getNumItems()),
                            i;


                        for (i = 1; i <= (isNext ? preloadAfter : preloadBefore); i++) {
                            self.lazyLoadItem(_currentItemIndex + i);
                        }
                        for (i = 1; i <= (isNext ? preloadBefore : preloadAfter); i++) {
                            self.lazyLoadItem(_currentItemIndex - i);
                        }
                    });

                    _listen('initialLayout', function() {
                        self.currItem.initialLayout = _options.getThumbBoundsFn && _options.getThumbBoundsFn(_currentItemIndex);
                    });

                    _listen('mainScrollAnimComplete', _appendImagesPool);
                    _listen('initialZoomInEnd', _appendImagesPool);



                    _listen('destroy', function() {
                        var item;
                        for (var i = 0; i < _items.length; i++) {
                            item = _items[i];
                            // remove reference to DOM elements, for GC
                            if (item.container) {
                                item.container = null;
                            }
                            if (item.placeholder) {
                                item.placeholder = null;
                            }
                            if (item.img) {
                                item.img = null;
                            }
                            if (item.preloader) {
                                item.preloader = null;
                            }
                            if (item.loadError) {
                                item.loaded = item.loadError = false;
                            }
                        }
                        _imagesToAppendPool = null;
                    });
                },


                getItemAt: function(index) {
                    if (index >= 0) {
                        return _items[index] !== undefined ? _items[index] : false;
                    }
                    return false;
                },

                allowProgressiveImg: function() {
                    // 1. Progressive image loading isn't working on webkit/blink 
                    //    when hw-acceleration (e.g. translateZ) is applied to IMG element.
                    //    That's why in PhotoSwipe parent element gets zoom transform, not image itself.
                    //    
                    // 2. Progressive image loading sometimes blinks in webkit/blink when applying animation to parent element.
                    //    That's why it's disabled on touch devices (mainly because of swipe transition)
                    //    
                    // 3. Progressive image loading sometimes doesn't work in IE (up to 11).

                    // Don't allow progressive loading on non-large touch devices
                    return _options.forceProgressiveLoading || !_likelyTouchDevice || _options.mouseUsed || screen.width > 1200;
                    // 1200 - to eliminate touch devices with large screen (like Chromebook Pixel)
                },

                setContent: function(holder, index) {

                    if (_options.loop) {
                        index = _getLoopedId(index);
                    }

                    var prevItem = self.getItemAt(holder.index);
                    if (prevItem) {
                        prevItem.container = null;
                    }

                    var item = self.getItemAt(index),
                        img;


                    if (!item) {
                        holder.el.innerHTML = '';
                        return;
                    }

                    // allow to override data
                    _shout('gettingData', index, item);

                    holder.index = index;
                    holder.item = item;

                    // base container DIV is created only once for each of 3 holders
                    var baseDiv = item.container = framework.createEl('pswp__zoom-wrap');

                    if (!item.src && item.html) {
                        if (item.html.tagName) {
                            baseDiv.appendChild(item.html);
                        } else {
                            baseDiv.innerHTML = item.html;
                        }
                    }

                    _checkForError(item);

                    _calculateItemSize(item, _viewportSize);

                    if (item.src && !item.loadError && !item.loaded) {

                        item.loadComplete = function(item) {

                            // gallery closed before image finished loading
                            if (!_isOpen) {
                                return;
                            }

                            // check if holder hasn't changed while image was loading
                            if (holder && holder.index === index) {
                                if (_checkForError(item, true)) {
                                    item.loadComplete = item.img = null;
                                    _calculateItemSize(item, _viewportSize);
                                    _applyZoomPanToItem(item);

                                    if (holder.index === _currentItemIndex) {
                                        // recalculate dimensions
                                        self.updateCurrZoomItem();
                                    }
                                    return;
                                }
                                if (!item.imageAppended) {
                                    if (_features.transform && (_mainScrollAnimating || _initialZoomRunning)) {
                                        _imagesToAppendPool.push({
                                            item: item,
                                            baseDiv: baseDiv,
                                            img: item.img,
                                            index: index,
                                            holder: holder,
                                            clearPlaceholder: true
                                        });
                                    } else {
                                        _appendImage(index, item, baseDiv, item.img, _mainScrollAnimating || _initialZoomRunning, true);
                                    }
                                } else {
                                    // remove preloader & mini-img
                                    if (!_initialZoomRunning && item.placeholder) {
                                        item.placeholder.style.display = 'none';
                                        item.placeholder = null;
                                    }
                                }
                            }

                            item.loadComplete = null;
                            item.img = null; // no need to store image element after it's added

                            _shout('imageLoadComplete', index, item);
                        };

                        if (framework.features.transform) {

                            var placeholderClassName = 'pswp__img pswp__img--placeholder';
                            placeholderClassName += (item.msrc ? '' : ' pswp__img--placeholder--blank');

                            var placeholder = framework.createEl(placeholderClassName, item.msrc ? 'img' : '');
                            if (item.msrc) {
                                placeholder.src = item.msrc;
                            }

                            _setImageSize(item, placeholder);

                            baseDiv.appendChild(placeholder);
                            item.placeholder = placeholder;

                        }




                        if (!item.loading) {
                            _preloadImage(item);
                        }


                        if (self.allowProgressiveImg()) {
                            // just append image
                            if (!_initialContentSet && _features.transform) {
                                _imagesToAppendPool.push({
                                    item: item,
                                    baseDiv: baseDiv,
                                    img: item.img,
                                    index: index,
                                    holder: holder
                                });
                            } else {
                                _appendImage(index, item, baseDiv, item.img, true, true);
                            }
                        }

                    } else if (item.src && !item.loadError) {
                        // image object is created every time, due to bugs of image loading & delay when switching images
                        img = framework.createEl('pswp__img', 'img');
                        img.style.opacity = 1;
                        img.src = item.src;
                        _setImageSize(item, img);
                        _appendImage(index, item, baseDiv, img, true);
                    }


                    if (!_initialContentSet && index === _currentItemIndex) {
                        _currZoomElementStyle = baseDiv.style;
                        _showOrHide(item, (img || item.img));
                    } else {
                        _applyZoomPanToItem(item);
                    }

                    holder.el.innerHTML = '';
                    holder.el.appendChild(baseDiv);
                },

                cleanSlide: function(item) {
                    if (item.img) {
                        item.img.onload = item.img.onerror = null;
                    }
                    item.loaded = item.loading = item.img = item.imageAppended = false;
                }

            }
        });

        /*>>items-controller*/

        /*>>tap*/
        /**
         * tap.js:
         *
         * Displatches tap and double-tap events.
         * 
         */

        var tapTimer,
            tapReleasePoint = {},
            _dispatchTapEvent = function(origEvent, releasePoint, pointerType) {
                var e = document.createEvent('CustomEvent'),
                    eDetail = {
                        origEvent: origEvent,
                        target: origEvent.target,
                        releasePoint: releasePoint,
                        pointerType: pointerType || 'touch'
                    };

                e.initCustomEvent('pswpTap', true, true, eDetail);
                origEvent.target.dispatchEvent(e);
            };

        _registerModule('Tap', {
            publicMethods: {
                initTap: function() {
                    _listen('firstTouchStart', self.onTapStart);
                    _listen('touchRelease', self.onTapRelease);
                    _listen('destroy', function() {
                        tapReleasePoint = {};
                        tapTimer = null;
                    });
                },
                onTapStart: function(touchList) {
                    if (touchList.length > 1) {
                        clearTimeout(tapTimer);
                        tapTimer = null;
                    }
                },
                onTapRelease: function(e, releasePoint) {
                    if (!releasePoint) {
                        return;
                    }

                    if (!_moved && !_isMultitouch && !_numAnimations) {
                        var p0 = releasePoint;
                        if (tapTimer) {
                            clearTimeout(tapTimer);
                            tapTimer = null;

                            // Check if taped on the same place
                            if (_isNearbyPoints(p0, tapReleasePoint)) {
                                _shout('doubleTap', p0);
                                return;
                            }
                        }

                        if (releasePoint.type === 'mouse') {
                            _dispatchTapEvent(e, releasePoint, 'mouse');
                            return;
                        }

                        var clickedTagName = e.target.tagName.toUpperCase();
                        // avoid double tap delay on buttons and elements that have class pswp__single-tap
                        if (clickedTagName === 'BUTTON' || framework.hasClass(e.target, 'pswp__single-tap')) {
                            _dispatchTapEvent(e, releasePoint);
                            return;
                        }

                        _equalizePoints(tapReleasePoint, p0);

                        tapTimer = setTimeout(function() {
                            _dispatchTapEvent(e, releasePoint);
                            tapTimer = null;
                        }, 300);
                    }
                }
            }
        });

        /*>>tap*/

        /*>>desktop-zoom*/
        /**
         *
         * desktop-zoom.js:
         *
         * - Binds mousewheel event for paning zoomed image.
         * - Manages "dragging", "zoomed-in", "zoom-out" classes.
         *   (which are used for cursors and zoom icon)
         * - Adds toggleDesktopZoom function.
         * 
         */

        var _wheelDelta;

        _registerModule('DesktopZoom', {

            publicMethods: {

                initDesktopZoom: function() {

                    if (_oldIE) {
                        // no zoom for old IE (<=8)
                        return;
                    }

                    if (_likelyTouchDevice) {
                        // if detected hardware touch support, we wait until mouse is used,
                        // and only then apply desktop-zoom features
                        _listen('mouseUsed', function() {
                            self.setupDesktopZoom();
                        });
                    } else {
                        self.setupDesktopZoom(true);
                    }

                },

                setupDesktopZoom: function(onInit) {

                    _wheelDelta = {};

                    var events = 'wheel mousewheel DOMMouseScroll';

                    _listen('bindEvents', function() {
                        framework.bind(template, events, self.handleMouseWheel);
                    });

                    _listen('unbindEvents', function() {
                        if (_wheelDelta) {
                            framework.unbind(template, events, self.handleMouseWheel);
                        }
                    });

                    self.mouseZoomedIn = false;

                    var hasDraggingClass,
                        updateZoomable = function() {
                            if (self.mouseZoomedIn) {
                                framework.removeClass(template, 'pswp--zoomed-in');
                                self.mouseZoomedIn = false;
                            }
                            if (_currZoomLevel < 1) {
                                framework.addClass(template, 'pswp--zoom-allowed');
                            } else {
                                framework.removeClass(template, 'pswp--zoom-allowed');
                            }
                            removeDraggingClass();
                        },
                        removeDraggingClass = function() {
                            if (hasDraggingClass) {
                                framework.removeClass(template, 'pswp--dragging');
                                hasDraggingClass = false;
                            }
                        };

                    _listen('resize', updateZoomable);
                    _listen('afterChange', updateZoomable);
                    _listen('pointerDown', function() {
                        if (self.mouseZoomedIn) {
                            hasDraggingClass = true;
                            framework.addClass(template, 'pswp--dragging');
                        }
                    });
                    _listen('pointerUp', removeDraggingClass);

                    if (!onInit) {
                        updateZoomable();
                    }

                },

                handleMouseWheel: function(e) {

                    if (_currZoomLevel <= self.currItem.fitRatio) {
                        if (_options.modal) {

                            if (!_options.closeOnScroll || _numAnimations || _isDragging) {
                                e.preventDefault();
                            } else if (_transformKey && Math.abs(e.deltaY) > 2) {
                                // close PhotoSwipe
                                // if browser supports transforms & scroll changed enough
                                _closedByScroll = true;
                                self.close();
                            }

                        }
                        return true;
                    }

                    // allow just one event to fire
                    e.stopPropagation();

                    // https://developer.mozilla.org/en-US/docs/Web/Events/wheel
                    _wheelDelta.x = 0;

                    if ('deltaX' in e) {
                        if (e.deltaMode === 1 /* DOM_DELTA_LINE */ ) {
                            // 18 - average line height
                            _wheelDelta.x = e.deltaX * 18;
                            _wheelDelta.y = e.deltaY * 18;
                        } else {
                            _wheelDelta.x = e.deltaX;
                            _wheelDelta.y = e.deltaY;
                        }
                    } else if ('wheelDelta' in e) {
                        if (e.wheelDeltaX) {
                            _wheelDelta.x = -0.16 * e.wheelDeltaX;
                        }
                        if (e.wheelDeltaY) {
                            _wheelDelta.y = -0.16 * e.wheelDeltaY;
                        } else {
                            _wheelDelta.y = -0.16 * e.wheelDelta;
                        }
                    } else if ('detail' in e) {
                        _wheelDelta.y = e.detail;
                    } else {
                        return;
                    }

                    _calculatePanBounds(_currZoomLevel, true);

                    var newPanX = _panOffset.x - _wheelDelta.x,
                        newPanY = _panOffset.y - _wheelDelta.y;

                    // only prevent scrolling in nonmodal mode when not at edges
                    if (_options.modal ||
                        (
                            newPanX <= _currPanBounds.min.x && newPanX >= _currPanBounds.max.x &&
                            newPanY <= _currPanBounds.min.y && newPanY >= _currPanBounds.max.y
                        )) {
                        e.preventDefault();
                    }

                    // TODO: use rAF instead of mousewheel?
                    self.panTo(newPanX, newPanY);
                },

                toggleDesktopZoom: function(centerPoint) {
                    centerPoint = centerPoint || { x: _viewportSize.x / 2 + _offset.x, y: _viewportSize.y / 2 + _offset.y };

                    var doubleTapZoomLevel = _options.getDoubleTapZoom(true, self.currItem);
                    var zoomOut = _currZoomLevel === doubleTapZoomLevel;

                    self.mouseZoomedIn = !zoomOut;

                    self.zoomTo(zoomOut ? self.currItem.initialZoomLevel : doubleTapZoomLevel, centerPoint, 333);
                    framework[(!zoomOut ? 'add' : 'remove') + 'Class'](template, 'pswp--zoomed-in');
                }

            }
        });


        /*>>desktop-zoom*/

        /*>>history*/
        /**
         *
         * history.js:
         *
         * - Back button to close gallery.
         * 
         * - Unique URL for each slide: example.com/&pid=1&gid=3
         *   (where PID is picture index, and GID and gallery index)
         *   
         * - Switch URL when slides change.
         * 
         */


        var _historyDefaultOptions = {
            history: false,
            galleryUID: 1
        };

        var _historyUpdateTimeout,
            _hashChangeTimeout,
            _hashAnimCheckTimeout,
            _hashChangedByScript,
            _hashChangedByHistory,
            _hashReseted,
            _initialHash,
            _historyChanged,
            _closedFromURL,
            _urlChangedOnce,
            _windowLoc,

            _supportsPushState,

            _getHash = function() {
                return _windowLoc.hash.substring(1);
            },
            _cleanHistoryTimeouts = function() {

                if (_historyUpdateTimeout) {
                    clearTimeout(_historyUpdateTimeout);
                }

                if (_hashAnimCheckTimeout) {
                    clearTimeout(_hashAnimCheckTimeout);
                }
            },

            // pid - Picture index
            // gid - Gallery index
            _parseItemIndexFromURL = function() {
                var hash = _getHash(),
                    params = {};

                if (hash.length < 5) { // pid=1
                    return params;
                }

                var i, vars = hash.split('&');
                for (i = 0; i < vars.length; i++) {
                    if (!vars[i]) {
                        continue;
                    }
                    var pair = vars[i].split('=');
                    if (pair.length < 2) {
                        continue;
                    }
                    params[pair[0]] = pair[1];
                }
                if (_options.galleryPIDs) {
                    // detect custom pid in hash and search for it among the items collection
                    var searchfor = params.pid;
                    params.pid = 0; // if custom pid cannot be found, fallback to the first item
                    for (i = 0; i < _items.length; i++) {
                        if (_items[i].pid === searchfor) {
                            params.pid = i;
                            break;
                        }
                    }
                } else {
                    params.pid = parseInt(params.pid, 10) - 1;
                }
                if (params.pid < 0) {
                    params.pid = 0;
                }
                return params;
            },
            _updateHash = function() {

                if (_hashAnimCheckTimeout) {
                    clearTimeout(_hashAnimCheckTimeout);
                }


                if (_numAnimations || _isDragging) {
                    // changing browser URL forces layout/paint in some browsers, which causes noticable lag during animation
                    // that's why we update hash only when no animations running
                    _hashAnimCheckTimeout = setTimeout(_updateHash, 500);
                    return;
                }

                if (_hashChangedByScript) {
                    clearTimeout(_hashChangeTimeout);
                } else {
                    _hashChangedByScript = true;
                }


                var pid = (_currentItemIndex + 1);
                var item = _getItemAt(_currentItemIndex);
                if (item.hasOwnProperty('pid')) {
                    // carry forward any custom pid assigned to the item
                    pid = item.pid;
                }
                var newHash = _initialHash + '&' + 'gid=' + _options.galleryUID + '&' + 'pid=' + pid;

                if (!_historyChanged) {
                    if (_windowLoc.hash.indexOf(newHash) === -1) {
                        _urlChangedOnce = true;
                    }
                    // first time - add new hisory record, then just replace
                }

                var newURL = _windowLoc.href.split('#')[0] + '#' + newHash;

                if (_supportsPushState) {

                    if ('#' + newHash !== window.location.hash) {
                        history[_historyChanged ? 'replaceState' : 'pushState']('', document.title, newURL);
                    }

                } else {
                    if (_historyChanged) {
                        _windowLoc.replace(newURL);
                    } else {
                        _windowLoc.hash = newHash;
                    }
                }



                _historyChanged = true;
                _hashChangeTimeout = setTimeout(function() {
                    _hashChangedByScript = false;
                }, 60);
            };





        _registerModule('History', {



            publicMethods: {
                initHistory: function() {

                    framework.extend(_options, _historyDefaultOptions, true);

                    if (!_options.history) {
                        return;
                    }


                    _windowLoc = window.location;
                    _urlChangedOnce = false;
                    _closedFromURL = false;
                    _historyChanged = false;
                    _initialHash = _getHash();
                    _supportsPushState = ('pushState' in history);


                    if (_initialHash.indexOf('gid=') > -1) {
                        _initialHash = _initialHash.split('&gid=')[0];
                        _initialHash = _initialHash.split('?gid=')[0];
                    }


                    _listen('afterChange', self.updateURL);
                    _listen('unbindEvents', function() {
                        framework.unbind(window, 'hashchange', self.onHashChange);
                    });


                    var returnToOriginal = function() {
                        _hashReseted = true;
                        if (!_closedFromURL) {

                            if (_urlChangedOnce) {
                                history.back();
                            } else {

                                if (_initialHash) {
                                    _windowLoc.hash = _initialHash;
                                } else {
                                    if (_supportsPushState) {

                                        // remove hash from url without refreshing it or scrolling to top
                                        history.pushState('', document.title, _windowLoc.pathname + _windowLoc.search);
                                    } else {
                                        _windowLoc.hash = '';
                                    }
                                }
                            }

                        }

                        _cleanHistoryTimeouts();
                    };


                    _listen('unbindEvents', function() {
                        if (_closedByScroll) {
                            // if PhotoSwipe is closed by scroll, we go "back" before the closing animation starts
                            // this is done to keep the scroll position
                            returnToOriginal();
                        }
                    });
                    _listen('destroy', function() {
                        if (!_hashReseted) {
                            returnToOriginal();
                        }
                    });
                    _listen('firstUpdate', function() {
                        _currentItemIndex = _parseItemIndexFromURL().pid;
                    });




                    var index = _initialHash.indexOf('pid=');
                    if (index > -1) {
                        _initialHash = _initialHash.substring(0, index);
                        if (_initialHash.slice(-1) === '&') {
                            _initialHash = _initialHash.slice(0, -1);
                        }
                    }


                    setTimeout(function() {
                        if (_isOpen) { // hasn't destroyed yet
                            framework.bind(window, 'hashchange', self.onHashChange);
                        }
                    }, 40);

                },
                onHashChange: function() {

                    if (_getHash() === _initialHash) {

                        _closedFromURL = true;
                        self.close();
                        return;
                    }
                    if (!_hashChangedByScript) {

                        _hashChangedByHistory = true;
                        self.goTo(_parseItemIndexFromURL().pid);
                        _hashChangedByHistory = false;
                    }

                },
                updateURL: function() {

                    // Delay the update of URL, to avoid lag during transition, 
                    // and to not to trigger actions like "refresh page sound" or "blinking favicon" to often

                    _cleanHistoryTimeouts();


                    if (_hashChangedByHistory) {
                        return;
                    }

                    if (!_historyChanged) {
                        _updateHash(); // first time
                    } else {
                        _historyUpdateTimeout = setTimeout(_updateHash, 800);
                    }
                }

            }
        });


        /*>>history*/
        framework.extend(self, publicMethods);
    };
    return PhotoSwipe;
}

export default PhotoSwipe();
